CVEvulnerability
CVE-2026-77118
8.4 HIGH
Official page ↗
- Status
- Deferred
- Published
- 2026-08-20
- Last modified
- 2026-10-27
- Assigner
- 22e2d327-25fe-45d7-9f0c-dcd23b7108df
- CVSS 4.0 (22e2d327-25fe-45d7-9f0c-dcd23b7108df)
- 8.4 HIGH — 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
- Weaknesses
- CWE-787
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.
Related
Weakness · CWE (1)
- CWE-787 Out-of-bounds Write weakness