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Fencer Vulns
medium 5.5

CVE-2026-42146 json

CImg Library: Uncontrolled memory allocation via nb_colors field in _load_bmp

published 2026-05-04 6 mo ago modified 2026-10-26 13 d ago also EUVD-2026-27077

cvss
5.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 7%
public exploits
0
none known

Summary

CImg Library is a C++ library for image processing. Prior to commit c3aacf5, the nb_colors field read from the BMP file header is used directly to compute an allocation size without validating it against the remaining file size. A crafted BMP file with a large nb_colors value triggers an out-of-memory condition, crashing any application that uses CImg to load untrusted BMP files. This issue has been patched via commit c3aacf5.

Patch / fix

  • cimg Debian 13 3.5.2+dfsg-1+deb13u1
  • cimg Debian 14 3.5.2+dfsg-2

debian advisories DEBIAN-CVE-2026-42146

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-42146 updated cvss 6.5

CImg: CImg Library: Denial of Service via crafted BMP file

  • Red Hat All currently supported Red Hat products
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
6 mo ago

Exploit prediction

0.18% chance of exploitation in the next 30 days, higher than 7% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/GreycLab/CImg/issues/477 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

Affected products

  • GreycLab CImg

Classification

Weakness
  • CWE-789 Memory Allocation with Excessive Size Value

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.