Update dependency axios to v0.31.1 [SECURITY]#317
Merged
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
This PR contains the following updates:
0.31.0→0.31.1Axios: Incomplete Fix for CVE-2025-62718 — NO_PROXY Protection Bypassed via RFC 1122 Loopback Subnet (127.0.0.0/8) in Axios 1.15.0
CVE-2026-42043 / GHSA-pmwg-cvhr-8vh7
More information
Details
1. Executive Summary
This report documents an incomplete security patch for the previously disclosed vulnerability GHSA-3p68-rc4w-qgx5 (CVE-2025-62718), which affects the
NO_PROXYhostname resolution logic in the Axios HTTP library.Background — The Original Vulnerability
The original vulnerability (GHSA-3p68-rc4w-qgx5) disclosed that Axios did not normalize hostnames before comparing them against
NO_PROXYrules. Specifically, a request tohttp://localhost./(with a trailing dot) orhttp://[::1]/(with IPv6 bracket notation) would bypass NO_PROXY matching entirely and be forwarded to the configured HTTP proxy — even whenNO_PROXY=localhost,127.0.0.1,::1was explicitly set by the developer to protect loopback services.The Axios maintainers addressed this in version 1.15.0 by introducing a
normalizeNoProxyHost()function inlib/helpers/shouldBypassProxy.js, which strips trailing dots from hostnames and removes brackets from IPv6 literals before performing the NO_PROXY comparison.The Incomplete Patch — This Finding
While the patch correctly addresses the specific cases reported (trailing dot normalization and IPv6 bracket removal), the fix is architecturally incomplete.
The patch introduced a hardcoded set of recognized loopback addresses:
However, RFC 1122 §3.2.1.3 explicitly defines the entire 127.0.0.0/8 subnet as the IPv4 loopback address block not just the single address
127.0.0.1. On all major operating systems (Linux, macOS, Windows with WSL), any IP address in the range127.0.0.2through127.255.255.254is a valid, functional loopback address that routes to the local machine.As a result, an attacker who can influence the target URL of an Axios request can substitute 127.0.0.1 with any other address in the
127.0.0.0/8range (e.g.,127.0.0.2,127.0.0.100,127.1.2.3) to completely bypass theNO_PROXYprotection even in the fully patched Axios 1.15.0 release.Verification
This bypass has been independently verified on:
The Proof-of-Concept demonstrates that while
localhost,localhost., and[::1]are correctly blocked by the patched version, requests to127.0.0.2,127.0.0.100, and127.1.2.3are transparently forwarded to the attacker-controlled proxy server, confirming that the patch does not cover the full RFC-defined loopback address space.2. Deep-Dive: Technical Root Cause Analysis
2.1 Vulnerable File & Location
2.2 How Axios Routes HTTP Requests The Call Chain
When Axios dispatches any HTTP request,
lib/adapters/http.jscallssetProxy(), which invokesshouldBypassProxy()to decide whether to honour a configured proxy:shouldBypassProxy()is the single gatekeeper for NO_PROXY enforcement. A bypass here means all proxy protection fails silently.2.3 The Original Vulnerability (GHSA-3p68-rc4w-qgx5)
Before Axios 1.15.0, hostnames were compared against
NO_PROXYusing a raw literal string match with no normalization:Both
localhost.(FQDN trailing dot, RFC 1034 §3.1) and[::1](bracketed IPv6 literal, RFC 3986 §3.2.2) are canonical representations of loopback addresses, but Axios treated them as unknown hosts.2.4 What the Patch Fixed (Axios 1.15.0)
The patch introduced three changes inside
lib/helpers/shouldBypassProxy.js:Fix A
normalizeNoProxyHost()(Lines 47–57)Strips alternate representations before comparison:
Fix B Cross-Loopback Equivalence (Lines 1–3 & 108)
Allows
127.0.0.1andlocalhostto match each other interchangeably:Fix C Normalization Applied on Both Sides (Lines 81 & 90)
2.5 The Incomplete Patch Exact Root Cause
The fundamental flaw resides in Line 1:
*RFC 1122 §3.2.1.3 is unambiguous:
This means all addresses from
127.0.0.1through127.255.255.254are valid loopback addresses on any RFC-compliant operating system. On Linux, the entire/8block is routed to thelointerface by default. The patch recognises only127.0.0.1, leaving16,777,213valid loopback addresses unprotected.2.6 Step-by-Step Bypass Execution Trace
Environment:
Annotated execution of shouldBypassProxy("http://127.0.0.2:9191/internal-api"):
2.7 Why the Patch Design Is Flawed
The patch addresses the symptom (two specific alternate representations) rather than the root cause (an incomplete definition of what constitutes a loopback address).
Real-world services that commonly bind to non-standard loopback addresses include:
3. Comprehensive Attack Vector & Proof of Concept
3.1 Reproduction Steps
Step 1 — Create a fresh project directory
Step 2 — Initialize the project with the patched Axios version
Create
package.json:Install dependencies:
Verify the installed version:
Step 3 — Create the PoC file (
poc.js)Step 4 — Execute the PoC
3.2 Observed Output
The following output was captured during testing on Kali Linux with Axios 1.15.0:
3.3 Analysis of Results
The output conclusively demonstrates the following:
Patched cases behave correctly: Requests to
localhost,localhost.(trailing dot), and[::1](bracketed IPv6) all result in a direct connection, confirming that the existing patch in Axios 1.15.0 correctly handles the cases reported in GHSA-3p68-rc4w-qgx5.Bypass cases confirm the incomplete patch: Requests to
127.0.0.2,127.0.0.100, and127.1.2.3all of which are valid loopback addresses within the127.0.0.0/8subnet as defined byRFC 1122 §3.2.1.3are transparently forwarded to the attacker-controlled proxy server. The proxy receives the full request including the HTTP method, target URL, andHostheader, demonstrating that any response from an internal service bound to these addresses would be fully intercepted.This confirms that the
NO_PROXYprotection configured by the developer (localhost,127.0.0.1,::1) fails silently for the entire127.0.0.0/8address range beyond127.0.0.1, providing a reproducible and reliable bypass of the security control introduced by the patch.4. Impact Assessment
This vulnerability is a security control bypass specifically an incomplete patch that allows an attacker to circumvent the
NO_PROXYprotection mechanism in Axios by using any loopback addresses within the127.0.0.0/8subnet other than127.0.0.1. The result is that traffic intended to remain private and direct is silently intercepted by a configured proxy server.4.1 Who Is Impacted?
Primary Target — Node.js Backend Applications
Any Node.js application that meets all three of the following conditions is vulnerable:
Affected Deployment Environments
Scale of Exposure
Axios is one of the most widely used HTTP client libraries in the JavaScript ecosystem, with over 500 million weekly downloads on npm. Any application in the above categories using Axios 1.15.0 is affected, regardless of whether the developer is aware of the underlying proxy routing logic.
4.3 Impact Details
Impact 1 Silent Interception of Internal Service Traffic
When an application makes a request to an internal loopback service using a non-standard loopback address (e.g.,
http://127.0.0.2/admin), Axios silently routes the request through the configured proxy instead of connecting directly.The developer receives no error or warning. From the application's perspective, the request succeeds normally.
Impact 2 — SSRF Mitigation Bypass
Many applications implement SSRF protections by configuring
NO_PROXYto prevent requests to loopback addresses from being forwarded externally. This bypass defeats that protection entirely for any loopback address beyond127.0.0.1.An attacker who can influence the target URL of an Axios request through user-supplied input, redirect chains, or other SSRF vectors can exploit this gap to reach internal services that the developer explicitly intended to protect.
Impact 3 — Cloud Metadata Service Exposure
In cloud environments (AWS, GCP, Azure), SSRF vulnerabilities are particularly severe because they can be used to access the instance metadata service and retrieve IAM credentials, enabling full cloud account compromise.
While the AWS IMDSv2 service is reachable at
169.254.169.254(not a loopback address), many cloud deployments run internal metadata proxies, credential servers, or service discovery endpoints bound to non-standard loopback addresses within the127.0.0.0/8range. An attacker reaching any of these services through the bypass could:Impact 4 — Confidential Data Exfiltration
Any internal service binding to a
127.x.x.xaddress other than127.0.0.1is fully exposed. This includes:Impact 5 — No Indication of Compromise
A particularly dangerous characteristic of this vulnerability is that it is completely silent neither the application nor the developer receives any indication that requests are being routed incorrectly. There are no error messages, no exceptions thrown, and no changes in application behaviour. The proxy interception is entirely transparent from the application's perspective, making detection extremely difficult without active network monitoring.
4.4 Comparison with Original Vulnerability
The severity of this finding is equivalent to the original vulnerability because the attack conditions, exploitation technique, and resulting impact are identical. The only difference is the specific input used to trigger the bypass, which the existing patch completely fails to address.
5. Technical Remediation & Proposed Fix
5.1 Vulnerable Code Block
The vulnerability resides in
lib/helpers/shouldBypassProxy.jsat lines 1–3. The following is the exact code extracted from Axios 1.15.0:This hardcoded
Setis subsequently used at line 108 during the final NO_PROXY match evaluation:Why this is dangerous: The
Setperforms a strict membership check. Any IPv4 loopback address outside the three hardcoded entries returnsfalse, causingshouldBypassProxy()to returnfalseand silently route the request through the configured proxy.5.2 Proposed Patched Code
Replace lines 1–3 in
lib/helpers/shouldBypassProxy.jswith the following RFC-compliant implementation:5.3 Diff View — Before vs After
All other code in
shouldBypassProxy.jsremains unchanged. No other files require modification.5.4 Why This Fix Must Be Applied
Reason 1 — RFC 1122 Compliance
The current implementation violates RFC 1122 §3.2.1.3, which defines the entire
127.0.0.0/8block as the IPv4 loopback address range not just the single address127.0.0.1. The proposed fix aligns Axios with the standard, ensuring that all valid loopback addresses are recognised and handled consistently.Reason 2 — The Existing Patch Has Already Failed Once
The patch for GHSA-3p68-rc4w-qgx5 was released with the explicit intent of securing NO_PROXY hostname matching for loopback addresses. Within the same release (1.15.0), the protection can be bypassed by substituting
127.0.0.1with any other address in the127.0.0.0/8range. Leaving this gap unaddressed means that the patch creates a false sense of security developers believe their loopback traffic is protected when it is not.Reason 3 — Real Operating System Behaviour
On Linux the dominant platform for Node.js server deployments the kernel routes the entire
127.0.0.0/8subnet to the loopback interfaceloby default. This means any address in that range functions identically to127.0.0.1at the networking level.Axios's current implementation does not reflect this operating system behaviour, resulting in an inconsistency between what the OS considers loopback and what Axios treats as loopback.
Reason 4 — The Proposed Fix Has Zero Performance Impact
The existing solution uses a
Set.has()lookup an O(1) operation. The proposed fix replaces this with:'localhost','::1') — O(1)split('.')and array validation — O(1) with a fixed-length array of 4 elementsThe computational cost is equivalent or lower than the current approach, and the fix introduces no new external dependencies.
Reason 5 — The Fix Is Minimal and Surgical
The proposed change modifies only 3 lines of a single file. It does not alter:
parseNoProxyEntry()functionnormalizeNoProxyHost()functionshouldBypassProxy()main function logicThis minimises regression risk and makes the fix straightforward to review, test, and backport to older supported branches.
Reason 6 — Resilient to Alternative IP Encodings
Because Axios normalises the request URL using Node's native
new URL()parser before passing it toshouldBypassProxy(), alternative IP encodings (such as octal0177.0.0.1, hex0x7f.0.0.1, or integer2130706433) are already resolved into their standard IPv4 dotted-decimal format. This means the proposed.split('.')validation logic is completely robust and cannot be bypassed using URL-encoded IP obfuscation techniques.5.5 Additional Recommendation — IPv6 Loopback Range
While the primary bypass demonstrated in this report targets the IPv4
127.0.0.0/8range, the Axios team should also consider validating the full IPv6 loopback representation. The current implementation recognises only::1. A more complete check would also handle the full-form notation:Normalising these representations before comparison would make the NO_PROXY implementation comprehensively RFC-compliant across both IPv4 and IPv6 address families.
Severity
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:NReferences
This data is provided by the GitHub Advisory Database (CC-BY 4.0).
Axios: XSRF Token Cross-Origin Leakage via Prototype Pollution Gadget in
withXSRFTokenBoolean CoercionCVE-2026-42042 / GHSA-xx6v-rp6x-q39c
More information
Details
Vulnerability Disclosure: XSRF Token Cross-Origin Leakage via Prototype Pollution Gadget in
withXSRFTokenBoolean CoercionSummary
The Axios library's XSRF token protection logic uses JavaScript truthy/falsy semantics instead of strict boolean comparison for the
withXSRFTokenconfig property. When this property is set to any truthy non-boolean value (via prototype pollution or misconfiguration), the same-origin check (isURLSameOrigin) is short-circuited, causing XSRF tokens to be sent to all request targets including cross-origin servers controlled by an attacker.Severity: Medium (CVSS 5.4)
Affected Versions: All versions since
withXSRFTokenwas introducedVulnerable Component:
lib/helpers/resolveConfig.js:59Environment: Browser-only (XSRF logic only runs when
hasStandardBrowserEnvis true)CWE
CVSS 3.1
Score: 5.4 (Medium)
Vector:
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:NUsage of "Helper" Vulnerabilities
This vulnerability requires Zero Direct User Input when triggered via prototype pollution.
If an attacker can pollute
Object.prototype.withXSRFTokenwith any truthy value (e.g.,1,"true",{}), Axios will automatically inherit this value during config merge. The truthy value short-circuits the same-origin check, causing the XSRF cookie value to be sent as a request header to every destination.Vulnerable Code
File:
lib/helpers/resolveConfig.js, lines 57-66Designed behavior:
true→ always send token (explicit cross-origin opt-in)false→ never send tokenundefined→ send only for same-origin requestsActual behavior for non-boolean truthy values (
1,"false",{},[]):Proof of Concept
Verified PoC Output
Impact Analysis
Object.prototype.withXSRFToken = 1affects every axios request in the applicationwithXSRFToken: "false"(string) instead offalse(boolean) triggers the same issue without PPLimitations:
hasStandardBrowserEnv)Recommended Fix
Use strict boolean comparison:
Resources
Timeline
Severity
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:NReferences
This data is provided by the GitHub Advisory Database (CC-BY 4.0).
Axios' HTTP adapter-streamed uploads bypass maxBodyLength when maxRedirects: 0
CVE-2026-42034 / GHSA-5c9x-8gcm-mpgx
More information
Details
Summary
For stream request bodies, maxBodyLength is bypassed when maxRedirects is set to 0 (native http/https transport path). Oversized streamed uploads are sent fully even when the caller sets strict body limits.
Details
Relevant flow in lib/adapters/http.js:
This creates a path-specific bypass for streamed uploads.
PoC
Environment:
Steps:
Observed:
Control checks:
Impact
Type: DoS / uncontrolled upstream upload / resource exhaustion.
Impacted: Node.js services using streamed request bodies with maxBodyLength expecting hard enforcement, especially when following Axios guidance to use maxRedirects: 0 for streams.
Severity
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:LReferences
This data is provided by the GitHub Advisory Database (CC-BY 4.0).
Axios: no_proxy bypass via IP alias allows SSRF
CVE-2026-42038 / GHSA-m7pr-hjqh-92cm
More information
Details
The fix for no_proxy hostname normalization bypass (#10661) is incomplete.When no_proxy=localhost is set, requests to 127.0.0.1 and [::1] still route through the proxy instead of bypassing it.
The shouldBypassProxy() function does pure string matching — it does not
resolve IP aliases or loopback equivalents. As a result:
POC :
process.env.no_proxy = 'localhost';
process.env.http_proxy = 'http://attacker-proxy:8888';
Why the Standard Flow Is NOT Affected
Proof of Concept
Verified PoC Output
Impact Analysis
Primary impact is limited because the standard axios request flow is not affected. However:
AxiosURLSearchParamsdirectly for custom serialization are affectedparamsSerializer.encodethat delegates to the internal encoder triggers the bugIf null bytes reach a downstream C-based parser, impacts include URL truncation, WAF bypass, and log injection.
Recommended Fix
Remove the
%00entry from charMap and update the regex:Resources
Timeline
Severity
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:NReferences
This data is provided by the GitHub Advisory Database (CC-BY 4.0).
Axios: unbounded recursion in toFormData causes DoS via deeply nested request data
CVE-2026-42039 / GHSA-62hf-57xw-28j9
More information
Details
Summary
toFormData recursively walks nested objects with no depth limit, so a deeply nested value passed as request data crashes the Node.js process with a RangeError.
Details
lib/helpers/toFormData.js:210 defines an inner
build(value, path)that recurses into every object/array child (line 225:build(el, path ? path.concat(key) : [key])). The only safeguard is astackarray used to detect circular references; there is no maximum depth and no try/catch around the recursion. Becausebuildcalls itself once per nesting level, a payload nested roughly 2000+ levels deep exhausts V8's call stack.toFormDatais the serializer behindFormDatarequest bodies andAxiosURLSearchParams(used bybuildURLwhenparamsis an object withURLSearchParamsunavailable, seelib/helpers/buildURL.js:53andlib/helpers/AxiosURLSearchParams.js:36). Any server-side code that forwards a client-supplied object intoaxios({ data, params })therefore reaches the recursive walker with attacker-controlled depth.The RangeError is thrown synchronously from inside
forEach, escapestoFormData, and propagates out of the axios request call. In typical Express/Fastify request handlers this terminates the running request; in synchronous startup paths or worker threads it can crash the whole process.PoC
Server-side reachability example:
Verified on axios 1.15.0 (latest, 2026-04-10), Node.js 20, 3/3 PoC runs reproduce the RangeError at depth 2500.
Impact
A remote, unauthenticated attacker who can influence an object passed to axios as request
dataorparamstriggers an uncaught RangeError inside the synchronous recursive walker. In server-side applications that proxy or re-send client JSON through axios this crashes the request handler and, in worker/cluster setups, the process. Fix by bounding recursion depth intoFormData'sbuildfunction (reject or throw on depths beyond a configurable limit, e.g. 100) or rewriting the walker iteratively.Severity
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:NReferences
This data is provided by the GitHub Advisory Database (CC-BY 4.0).
Release Notes
axios/axios (axios)
v0.31.1Compare Source
This release backports a broad set of security hardenings from the v1 line — covering prototype-pollution defences, stream size enforcement, XSRF handling, URL null-byte encoding, and bounded FormData recursion — and drops committed
dist/artefacts along with Bower support.dist/Removed:dist/bundles are no longer committed to the repo, andbower.jsonplus the Gruntpackage2bowertask have been removed. CI still builds bundles before publish, so npm/yarn/pnpm consumers are unaffected; installs via Bower or directly from the git tree must migrate to npm or a CDN. (#10747)🔒 Security Fixes
isFormDatato reject plain/null-prototype objects and requireappend, and guarded the Node HTTP adapter sodata.getHeaders()is only merged when it is not inherited fromObject.prototype. Blocks injected headers via pollutedgetHeaders. (#10750)mergeConfig, defaults resolution, and the HTTP adapter now uses own-property checks fortransport,env,Blob,formSerializer, and transforms arrays, and merged configs are returned as null-prototype objects. Prevents hijacking of the request flow through polluted prototypes. (#10752)maxDepth(default100,Infinitydisables) totoFormDataand params serialisation, throwingAxiosErrorwith codeERR_FORM_DATA_DEPTH_EXCEEDEDwhen exceeded. Circular-reference detection is preserved. (#10728)%00→ null-byte substitution fromAxiosURLSearchParams.encodeso%00is preserved as-is. Other encoding behaviour (including%20→+) unchanged. (#10737)v0.x:maxContentLengthenforcement forresponseType: 'stream'via a guarded transform with deferred piping,maxBodyLengthenforcement for streamed uploads on nativehttp/httpswithmaxRedirects: 0, and stricterwithXSRFTokenhandling so only own booleantrueenables cross-origin XSRF headers. (#10764)🔧 Maintenance & Chores
.github/CODEOWNERSwith* @​jasonsaaymanto set a default reviewer for all paths. (#10740)Full Changelog
Configuration
📅 Schedule: (in timezone Asia/Tokyo)
🚦 Automerge: Enabled.
♻ Rebasing: Whenever PR is behind base branch, or you tick the rebase/retry checkbox.
🔕 Ignore: Close this PR and you won't be reminded about this update again.
This PR was generated by Mend Renovate. View the repository job log.