CVE-2026-21487: iccDEV Memory Corruption Vulnerability

CVE-2026-21487 Overview

CVE-2026-21487 is an Out-of-Bounds Read vulnerability affecting iccDEV, a library and toolset for working with ICC color management profiles. The vulnerability exists in the CIccProfile::LoadTag function where improper input validation allows an attacker to trigger out-of-bounds memory reads through maliciously crafted ICC profile files. Versions 2.3.1.1 and below are affected, with the issue being addressed in version 2.3.1.2.

Critical Impact
Attackers can craft malicious ICC profile files to cause application crashes through out-of-bounds memory access or potentially leak sensitive memory contents. Applications processing untrusted ICC profiles are at risk.

Affected Products

iccDEV versions 2.3.1.1 and below
Applications and software utilizing the iccDEV library for ICC color profile processing
Systems processing untrusted ICC color management profiles

Discovery Timeline

January 6, 2026 - CVE-2026-21487 published to NVD
January 8, 2026 - Last updated in NVD database

Technical Details for CVE-2026-21487

Vulnerability Analysis

The vulnerability resides in the CIccProfile::LoadTag function within the iccDEV library. The function failed to properly validate tag size information against the actual file boundaries before processing. When parsing an ICC profile, the function reads tag metadata including offset and size values from the profile structure. Without adequate validation, these values could specify memory regions extending beyond the actual file content, resulting in out-of-bounds memory access.

The vulnerability encompasses three related weaknesses: Out-of-bounds Read (reading memory beyond allocated buffer boundaries), Use of Out-of-range Pointer Offset (calculating invalid memory addresses), and Improper Input Validation (CWE-20) as the root cause. This combination allows attackers to craft ICC profiles with manipulated tag entries that reference memory regions outside the legitimate file data.

Root Cause

The root cause is improper input validation in the CIccProfile::LoadTag function. The code did not verify that the sum of a tag's offset and size fell within the actual file length. This allowed malformed ICC profiles to declare tag boundaries extending beyond the file, causing the application to read unallocated memory when processing these tags.

Attack Vector

This is a local attack vector requiring user interaction. An attacker must convince a victim to open a specially crafted ICC color profile file using an application that utilizes the vulnerable iccDEV library. The attack scenario typically involves:

Creating a malicious ICC profile with manipulated tag offset and size values
Distributing the malicious file through phishing, malicious websites, or compromised image files embedding ICC profiles
When the victim opens the file, the vulnerable LoadTag function reads beyond file boundaries
This can cause application crashes (denial of service) or potentially leak memory contents

cpp

   if (pTagEntry->pTag)
     return pTagEntry->pTag->ReadAll();
 
+  // if the tag claims to be inside the header, or zero length, return an error
   if (pTagEntry->TagInfo.offset<sizeof(m_Header) ||
     !pTagEntry->TagInfo.size) {
     return false;
   }
+  
+  // if the tag claims to be longer than the actual file, return an error
+  // NOTE - ccox - it would be nice to cache the file length instead of calculating it per tag
+  if ( (pTagEntry->TagInfo.offset + pTagEntry->TagInfo.size) > pIO->GetLength())
+    return false;
 
   icTagTypeSignature sigType;

Source: GitHub Commit Update

The patch adds a critical bounds check validating that the tag's declared offset plus size does not exceed the actual file length, preventing out-of-bounds access.

Detection Methods for CVE-2026-21487

Indicators of Compromise

Application crashes when processing ICC profile files, particularly with access violation or segmentation fault errors
Unusual memory access patterns or error logs in applications using iccDEV library
Malformed ICC profile files with tag entries specifying offsets or sizes exceeding file boundaries
Core dumps or crash reports indicating failures in CIccProfile::LoadTag or related functions

Detection Strategies

Monitor for application crashes or exceptions in software utilizing the iccDEV library during ICC profile processing
Implement file integrity checks on ICC profiles before processing, validating tag metadata against file size
Deploy endpoint detection solutions that can identify exploitation attempts through memory access violation patterns
Use static analysis tools to identify applications linked against vulnerable iccDEV versions

Monitoring Recommendations

Configure crash reporting and logging for applications that process ICC color profiles
Implement file type verification and input validation at application entry points
Monitor system logs for repeated application failures when handling image or color profile files
Consider sandboxing applications that process untrusted ICC profiles to limit impact

How to Mitigate CVE-2026-21487

Immediate Actions Required

Upgrade iccDEV to version 2.3.1.2 or later which contains the security fix
Audit applications in your environment that utilize the iccDEV library for ICC color profile processing
Consider temporarily restricting processing of ICC profiles from untrusted sources until patching is complete
Review the GitHub Security Advisory GHSA-xq7x-9524-f7cp for additional guidance

Patch Information

The vulnerability is fixed in iccDEV version 2.3.1.2. The patch adds a boundary check in the CIccProfile::LoadTag function that validates the tag offset plus size does not exceed the actual file length before attempting to read tag data. The fix can be reviewed in the GitHub commit 1516e2cafc253bb06fd3700d589a4ed0f09f7bd6.

Workarounds

Validate ICC profile files before processing by checking that all tag offset and size values fall within the file boundaries
Implement application-level sandboxing to contain potential crashes and memory disclosure
Configure applications to reject ICC profiles from untrusted sources pending the patch deployment
Use memory-safe wrapper functions or additional validation layers when calling iccDEV functions

bash

# Verify iccDEV version to confirm vulnerability status
# Check if your application links against vulnerable versions
ldd /path/to/application | grep -i icc

# If using package manager, verify version
# Example for checking library version
strings /path/to/libiccDEV.so | grep -i version