CVE-2026-21504 – CVE-2026-21504 is a heap buffer overflow vulner... (How to Fix)

Q: What is the severity of CVE-2026-21504?

CVE-2026-21504 has a CVSS score of 6.6 (MEDIUM). CVE-2026-21504 is a heap buffer overflow vulnerability in the ToneMap parser of iccDEV color management libraries. This allows attackers to execute arbitrary code or cause denial of service by processing malicious ICC color profiles. Users of iccDEV libraries or applications that incorporate them are affected.

📋 TL;DR

CVE-2026-21504 is a heap buffer overflow vulnerability in the ToneMap parser of iccDEV color management libraries. This allows attackers to execute arbitrary code or cause denial of service by processing malicious ICC color profiles. Users of iccDEV libraries or applications that incorporate them are affected.

💻 Affected Systems

Products:

iccDEV library
Applications using iccDEV for ICC profile processing

Versions: All versions prior to 2.3.1.2

Operating Systems: All platforms where iccDEV is used

Default Config Vulnerable: ⚠️ Yes

Notes: Any application that uses iccDEV to parse ICC color profiles is vulnerable by default.

📦 What is this software?

Iccdev by Color

View all CVEs affecting Iccdev →

⚠️ Risk & Real-World Impact

🔴

Worst Case

Remote code execution leading to complete system compromise, data theft, or ransomware deployment.

🟠

Likely Case

Application crash or denial of service affecting color processing functionality.

🟢

If Mitigated

Limited impact with proper memory protections (ASLR, DEP) and sandboxing.

🌐 Internet-Facing: MEDIUM - Requires processing malicious ICC files, which could be delivered via web uploads or email attachments.

🏢 Internal Only: LOW - Typically requires user interaction to process malicious files.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ⚠️ Yes

Complexity: MEDIUM

Exploitation requires crafting a malicious ICC profile file that triggers the buffer overflow during ToneMap parsing.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: 2.3.1.2

Vendor Advisory: https://github.com/InternationalColorConsortium/iccDEV/security/advisories

Restart Required: Yes

Instructions:

1. Identify applications using iccDEV. 2. Update iccDEV to version 2.3.1.2 or later. 3. Rebuild applications with updated library. 4. Restart affected services.

🔧 Temporary Workarounds

Disable ICC profile processing

all

Temporarily disable or restrict processing of external ICC color profiles in applications.

Input validation for ICC files

all

Implement strict validation and sanitization of ICC profile files before processing.

🧯 If You Can't Patch

Implement application sandboxing to limit potential damage from exploitation
Deploy memory protection mechanisms (ASLR, DEP) and monitor for crashes

🔍 How to Verify

Check if Vulnerable:

Check if applications link to iccDEV library version < 2.3.1.2 using ldd (Linux) or dependency walker tools.

Check Version:

For Linux: pkg-config --modversion iccdev or check library version in /usr/lib/libiccdev*

Verify Fix Applied:

Verify iccDEV version is 2.3.1.2 or higher and applications have been rebuilt with the updated library.

📡 Detection & Monitoring

Log Indicators:

Application crashes during ICC profile processing
Memory access violation errors in application logs

Network Indicators:

Unusual uploads of ICC profile files to web applications

SIEM Query:

source="application_logs" AND ("segmentation fault" OR "access violation" OR "heap corruption") AND "icc"

📊 Metadata

CVE ID: CVE-2026-21504

CVSS v3 Score: 6.6 (MEDIUM)

CVSS Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:H

CWE: CWE-122

EPSS Score: 0.01% exploit probability (1.8th percentile)

Published: January 7, 2026

Last Updated: January 9, 2026

🔗 References

📤 Share & Export

📄 Export Markdown 📋 Export JSON

🔗 Related Vulnerabilities

If you're affected by CVE-2026-21504, you might also want to check these: