CVE-2026-77118

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.

CVSS

No CVSS.

References

Link	Resource
https://foss.heptapod.net/graphicsmagick/graphicsmagick/-/commit/937cdd9920bd96
https://foss.heptapod.net/graphicsmagick/graphicsmagick/-/raw/GraphicsMagick-1_3_48/ChangeLog

Configurations

No configuration.

History

No history.

Information

Published : 2026-08-20 13:19

Updated : 2026-09-09 15:52

NVD link : CVE-2026-77118

Mitre link : CVE-2026-77118

CVE.ORG link : CVE-2026-77118

JSON object : View

Products Affected

No product.

CWE

CWE-787

Out-of-bounds Write

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