diff --git a/changelog.d/unreleased/3025.fixed.md b/changelog.d/unreleased/3025.fixed.md
new file mode 100644
index 0000000000..09c01df2d1
--- /dev/null
+++ b/changelog.d/unreleased/3025.fixed.md
@@ -0,0 +1,16 @@
+---
+category: fixed
+issues:
+  - 3025
+affected:
+  - src/CodeIndex/Cli/ConsoleUi.cs
+  - tests/CodeIndex.Tests/ConsoleUiTests.cs
+---
+
+## English
+
+- **Version metadata loading now falls back on invalid files (#3025)** — malformed, missing, unreadable, or schema-invalid `version.json` files no longer throw from CLI version-display paths and instead return the existing `0.0.0` fallback.
+
+## 日本語
+
+- **不正な version metadata 読み込み時に fallback するようになりました (#3025)** — malformed、missing、unreadable、schema-invalid な `version.json` でも CLI の version 表示経路で例外を投げず、既存の `0.0.0` fallback を返します。
diff --git a/changelog.d/unreleased/3244.fixed.md b/changelog.d/unreleased/3244.fixed.md
new file mode 100644
index 0000000000..8b902792c6
--- /dev/null
+++ b/changelog.d/unreleased/3244.fixed.md
@@ -0,0 +1,16 @@
+---
+category: fixed
+issues:
+  - 3244
+affected:
+  - src/CodeIndex/Cli/ConsoleUi.cs
+  - tests/CodeIndex.Tests/ConsoleUiTests.cs
+---
+
+## English
+
+- **Version metadata reads are now bounded (#3244)** — `version.json` loading now reads at most 16 KiB and parses with an explicit JSON depth limit before falling back to `0.0.0` on invalid metadata.
+
+## 日本語
+
+- **version metadata の読み込みに上限を設定しました (#3244)** — `version.json` の読み込みは最大 16 KiB になり、明示的な JSON depth 上限で parse したうえで、不正な metadata では `0.0.0` に fallback します。
diff --git a/src/CodeIndex/Cli/ConsoleUi.cs b/src/CodeIndex/Cli/ConsoleUi.cs
index 9ea82aebce..fe66e6528e 100644
--- a/src/CodeIndex/Cli/ConsoleUi.cs
+++ b/src/CodeIndex/Cli/ConsoleUi.cs
@@ -4,6 +4,7 @@
 using System.Reflection;
 using System.Runtime.InteropServices;
 using System.Text;
+using System.Text.Json;
 
 namespace CodeIndex.Cli;
 
@@ -67,6 +68,14 @@ public static class ConsoleUi
     public const string DisableProgressEnvironmentVariable = "CDIDX_DISABLE_PROGRESS";
     public const string PrefersReducedMotionEnvironmentVariable = "PREFERS_REDUCED_MOTION";
     public const int SummaryLabelWidth = 9;
+    internal const int MaxVersionJsonBytes = 16 * 1024;
+    internal const int MaxVersionJsonDepth = 8;
+    private const string FallbackVersion = "0.0.0";
+
+    private static readonly JsonDocumentOptions VersionJsonDocumentOptions = new()
+    {
+        MaxDepth = MaxVersionJsonDepth,
+    };
 
     private static readonly (string Command, string Usage)[] CommandUsageLines =
     [
@@ -714,13 +723,32 @@ public static string LoadVersion()
         }
         var ioPath = LongPath.EnsureWindowsPrefix(path);
         if (File.Exists(ioPath))
+            return LoadVersionFromFile(ioPath);
+
+        return FallbackVersion;
+    }
+
+    internal static string LoadVersionFromFile(string ioPath)
+    {
+        try
         {
-            var json = File.ReadAllText(ioPath);
-            using var doc = System.Text.Json.JsonDocument.Parse(json);
+            var json = DataDirectorySecurity.ReadTextWithinLimit(ioPath, MaxVersionJsonBytes);
+            if (json is null)
+                return FallbackVersion;
+
+            using var doc = JsonDocument.Parse(json, VersionJsonDocumentOptions);
             if (doc.RootElement.TryGetProperty("version", out var ver))
-                return ver.GetString() ?? "0.0.0";
+                return ver.GetString() ?? FallbackVersion;
         }
-        return "0.0.0";
+        catch (Exception ex) when (ex is IOException
+            or UnauthorizedAccessException
+            or JsonException
+            or InvalidOperationException)
+        {
+            return FallbackVersion;
+        }
+
+        return FallbackVersion;
     }
 
     /// <summary>
diff --git a/tests/CodeIndex.Tests/ConsoleUiTests.cs b/tests/CodeIndex.Tests/ConsoleUiTests.cs
index 3615332ed7..7d9f7f1bd6 100644
--- a/tests/CodeIndex.Tests/ConsoleUiTests.cs
+++ b/tests/CodeIndex.Tests/ConsoleUiTests.cs
@@ -640,6 +640,83 @@ public void LoadVersion_ReturnsActualVersion_NotFallback()
         Assert.Contains('.', version);
     }
 
+    [Fact]
+    public void LoadVersionFromFile_MalformedJson_ReturnsFallback()
+    {
+        var path = WriteTempVersionJson("""{"version":""");
+        try
+        {
+            Assert.Equal("0.0.0", ConsoleUi.LoadVersionFromFile(path));
+        }
+        finally
+        {
+            File.Delete(path);
+        }
+    }
+
+    [Fact]
+    public void LoadVersionFromFile_NonStringVersion_ReturnsFallback()
+    {
+        var path = WriteTempVersionJson("""{"version":{}}""");
+        try
+        {
+            Assert.Equal("0.0.0", ConsoleUi.LoadVersionFromFile(path));
+        }
+        finally
+        {
+            File.Delete(path);
+        }
+    }
+
+    [Fact]
+    public void LoadVersionFromFile_MissingFile_ReturnsFallback()
+    {
+        var path = Path.Combine(Path.GetTempPath(), $"cdidx_missing_version_{Guid.NewGuid():N}.json");
+
+        Assert.Equal("0.0.0", ConsoleUi.LoadVersionFromFile(path));
+    }
+
+    [Fact]
+    public void LoadVersionFromFile_OversizedJson_ReturnsFallback()
+    {
+        var path = WriteTempVersionJson("{\"version\":\"" + new string('1', ConsoleUi.MaxVersionJsonBytes) + "\"}");
+        try
+        {
+            Assert.Equal("0.0.0", ConsoleUi.LoadVersionFromFile(path));
+        }
+        finally
+        {
+            File.Delete(path);
+        }
+    }
+
+    [Fact]
+    public void LoadVersionFromFile_TooDeepJson_ReturnsFallback()
+    {
+        var nesting = ConsoleUi.MaxVersionJsonDepth + 1;
+        var path = WriteTempVersionJson(
+            """{"version":"1.2.3","nested":"""
+            + new string('[', nesting)
+            + "0"
+            + new string(']', nesting)
+            + "}");
+        try
+        {
+            Assert.Equal("0.0.0", ConsoleUi.LoadVersionFromFile(path));
+        }
+        finally
+        {
+            File.Delete(path);
+        }
+    }
+
+    private static string WriteTempVersionJson(string content)
+    {
+        var path = Path.Combine(Path.GetTempPath(), $"cdidx_version_{Guid.NewGuid():N}.json");
+        File.WriteAllText(path, content, Encoding.UTF8);
+        return path;
+    }
+
     [Fact]
     public void LoadBuildMetadata_PopulatesAllFields()
     {