CVE-2026-42146Public exploit

Application crash via unbounded BMP color allocation

Published May 4, 2026 · Updated May 4, 2026

Excessive memory allocation in CImg before commit c3aacf5 allows attackers to crash host applications through a crafted BMP file. The _load_bmp routine passes the header-controlled nb_colors value to colormap.assign without limiting it to the palette size permitted by the BMP bit depth. A user or consuming application must load the malicious file; successful exploitation exhausts process memory without reported data disclosure or modification.

CVSS severity5.5
Medium
EPSS probability0.12%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Excessive memory allocation in CImg before commit c3aacf5 allows attackers to crash host applications through a crafted BMP file. The _load_bmp routine passes the header-controlled nb_colors value to colormap.assign without limiting it to the palette size permitted by the BMP bit depth. A user or consuming application must load the malicious file; successful exploitation exhausts process memory without reported data disclosure or modification.

The record

CVE
CVE-2026-42146
Published
May 4, 2026
Updated
May 4, 2026
Vendor
GREYC
Product
CImg
Classifications
CWE-789, T1204.002
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 4, 2026CVE publishedPublication date reported by the CVE source.
  2. May 4, 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=< c3aacf5b96ac1e54b7af1957c6737dbf3949f6d3

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

GREYC · CImgversion=< c3aacf5b96ac1e54b7af1957c6737dbf3949f6d3

Published CVSS scores

5.5GitHubCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-789Memory Allocation with Excessive Size Value
T1204.002Malicious File

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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