CVE-2026-21677Public exploitNetwork attack vector

Undefined behavior via unchecked CLUT channel counts

Published Jan 6, 2026 · Updated Jan 6, 2026

Improper input validation in iccDEV before 2.3.1.1 allows remote attackers to trigger undefined behavior through a crafted ICC profile. CIccCLUT::Init accepts zero input or output channel counts, then derives an array index from m_nInput without rejecting the invalid dimensions. Public sources do not identify a deterministic runtime consequence, and exploitation requires user interaction to process the attacker-supplied profile.

CVSS severity8.8
High
EPSS probability0.36%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper input validation in iccDEV before 2.3.1.1 allows remote attackers to trigger undefined behavior through a crafted ICC profile. CIccCLUT::Init accepts zero input or output channel counts, then derives an array index from m_nInput without rejecting the invalid dimensions. Public sources do not identify a deterministic runtime consequence, and exploitation requires user interaction to process the attacker-supplied profile.

The record

CVE
CVE-2026-21677
Published
Jan 6, 2026
Updated
Jan 6, 2026
Vendor
International Color Consortium
Product
iccDEV
Classifications
CWE-758, CWE-20, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 6, 2026CVE publishedPublication date reported by the CVE source.
  2. Jan 6, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 2.3.1.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

International Color Consortium · iccDEVversion=< 2.3.1.1

Published CVSS scores

8.8GitHubCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-758Reliance on Undefined, Unspecified, or Implementation-Defined Behavior
CWE-20Improper Input Validation
T1203Exploitation for Client Execution

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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