VulnerabilityPublished 4 May 2026

CVE-2026-42144: GreycLab CImg · Integer Overflow or Wraparound

Affects GreycLab CImgSource CVE Database V5

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Not known to be exploited · CVSS 6.1 Medium.

Data as of 1 Nov 2026, 22:58 UTC

CVSS 3.1 base score

6.1Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.1% chance of exploitation in 30 days – higher than 3% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

Attack Vector: Local
Attack Complexity: Low
Privileges Required: None
User Interaction: Required
Scope: Unchanged
Confidentiality: None
Integrity: Low
Availability: High

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Local: The vulnerable component is not bound to the network stack and the attacker’s path is via read/write/execute capabilities. Either: the attacker exploits the vulnerability by accessing the target system locally (e.g., keyboard, console), or remotely (e.g., SSH); or the attacker relies on User Interaction by another person to perform actions required to exploit the vulnerability (e.g., tricking a legitimate user into opening a malicious document).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: Required: Successful exploitation of this vulnerability requires a user to take some action before the vulnerability can be exploited.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 4 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 1 Nov 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
GreycLabCImg	Affected =< 4ca26bce4d8c61fcd1507d5f9401b9fb1222c27d	Fixed in–

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AI-suggested

A patch addressing this vulnerability has been committed in CImg at commit 4ca26bce4d8c61fcd1507d5f9401b9fb1222c27d. Users and developers should update to this fixed version or later to remediate the issue. Since this is a library vulnerability, applications using CImg should incorporate the patched library version before processing untrusted image files. No additional vendor advisory is available; patch status is confirmed by the commit reference.

Description

CVE-2026-42144 is an integer overflow vulnerability in the CImg library used for image processing. The flaw occurs in the size calculation of image dimensions within the _load_pnm() function, where large dimension values cause an overflow that bypasses memory allocation checks. This results in an undersized buffer allocation and can lead to a heap buffer overflow when loading crafted PNM/PGM/PPM image files. The vulnerability affects all versions of CImg prior to commit 4ca26bce4d8c61fcd1507d5f9401b9fb1222c27d. A patch addressing this issue has been committed. The CVSS score is 6.1, indicating a medium severity level. No known exploits are reported in the wild, and the product is not a cloud service.

Impact

Successful exploitation can cause a heap buffer overflow, which may lead to application crashes or potentially enable an attacker to execute arbitrary code or cause denial of service. The impact is limited to applications using vulnerable versions of CImg to load untrusted PNM/PGM/PPM image files. The CVSS score of 6.1 reflects a medium severity with local attack vector, low attack complexity, no privileges required, and user interaction needed. There are no known exploits in the wild at this time.

Summary

The CImg library contains an integer overflow vulnerability (CWE-190) in the _load_pnm() function prior to commit 4ca26bce4d8c61fcd1507d5f9401b9fb1222c27d. This overflow occurs during the multiplication of image dimensions (width, height, depth) for memory allocation, allowing an attacker to craft a PNM/PGM/PPM image file with large dimension values that cause the size calculation to wrap around. This leads to allocation of a buffer smaller than required, potentially triggering a heap buffer overflow when the image is processed. The issue affects any application using vulnerable versions of CImg to load untrusted image files. The vulnerability has been patched in the specified commit.

CWE-190Integer Overflow or Wraparound (opens in a new tab)
Base weaknessLikelihood of exploit: Medium
The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.
Requirements
Ensure that all protocols are strictly defined, such that all out-of-bounds behavior can be identified simply, and require strict conformance to the protocol.
Requirements · Language Selection
Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
Architecture and Design · Libraries or Frameworks
Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
OWASP Cheat Sheets
XML Security (opens in a new tab)
Mass Assignment (opens in a new tab)
OWASP ASVS 4.0.3
V5.4.3 (opens in a new tab)
V13.3.1 (opens in a new tab)
V5.1.4 (opens in a new tab)
Attack patterns
Forced Integer Overflow (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 12 May 2026, 06:24 UTC

WeaknessesCWE-190

Technical details

References

Community reviews

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