CVE-2026-77118

Published: Ago 20, 2026 Last Modified: Ago 20, 2026
ExploitDB:
Other exploit source:
Google Dorks:
HIGH 8,4
Source: 22e2d327-25fe-45d7-9f0c-dcd23b7108df
Attack Vector: local
Attack Complexity: low
Privileges Required: none
User Interaction: active
Confidentiality: N/A
Integrity: N/A
Availability: N/A

Description

AI Translation Available

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.

787

Out-of-bounds Write

Draft
Abstraction: Base Structure: Simple
Common Consequences
Security Scopes Affected:
Integrity Availability Other
Potential Impacts:
Modify Memory Execute Unauthorized Code Or Commands Dos: Crash, Exit, Or Restart Unexpected State
Applicable Platforms
Languages: Memory-Unsafe, C, C++, Assembly
Technologies: ICS/OT
Likelihood of Exploit: High
View CWE Details
https://foss.heptapod.net/graphicsmagick/graphicsmagick/-/c…
https://foss.heptapod.net/graphicsmagick/graphicsmagick/-/commit/937cdd9920bd96
https://foss.heptapod.net/graphicsmagick/graphicsmagick/-/r…
https://foss.heptapod.net/graphicsmagick/graphicsmagick/-/raw/GraphicsMagick-1_…