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National Vulnerability Database

National Vulnerability Database

NVD

National Vulnerability Database
  1. Vulnerabilities

CVE-2026-77118 Detail

Description

A heap out-of-bounds write exists in the Photo CD (PCD) decoder of GraphicsMagick. In DecodeImage() (coders/pcd.c), the Huffman delta loop advances its output pointer with q++ after every decoded delta and never checks it against the end of the heap-allocated luma/chroma plane buffers. The pointer is repositioned only when a sync marker introduces a new plane/row; between sync markers the run length is bounded solely by the input. A crafted PCD file that positions the pointer near the end of a plane and then supplies a long run of deltas with no intervening sync therefore walks the pointer past the end of the allocation and writes through it. Processing an untrusted PCD file — for example with gm convert or gm identify, or through any application linked against libGraphicsMagick — can corrupt heap memory beyond the buffers.


Metrics

 
NVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed.
CVSS 4.0 Severity and Vector Strings:

NIST CVSS score
NIST: NVD
N/A
NVD assessment not yet provided.

Nist CVSS score does not match with CNA score
CNA:  seal
CVSS-B 8.4 HIGH
Vector:  CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

References to Advisories, Solutions, and Tools

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URL Source(s) Tag(s)
https://foss.heptapod.net/graphicsmagick/graphicsmagick/-/commit/937cdd9920bd96 seal
https://foss.heptapod.net/graphicsmagick/graphicsmagick/-/raw/GraphicsMagick-1_3_48/ChangeLog seal

Weakness Enumeration

CWE-ID CWE Name Source
CWE-787 Out-of-bounds Write seal  

Change History

1 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2026-77118
NVD Published Date:
08/20/2026
NVD Last Modified:
08/20/2026
Source:
seal