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
Affected Vendors & Products
References
History
Fri, 21 Aug 2026 12:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Debian graphicsmagick
Fedora Project Fedora Project graphicsmagick |
|
| Vendors & Products |
Debian graphicsmagick
Fedora Project Fedora Project graphicsmagick |
Thu, 20 Aug 2026 13:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| 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. | |
| Title | Out-of-bounds write in GraphicsMagick PCD decoder | |
| First Time appeared |
Debian
Debian debian Linux Fedoraproject Fedoraproject extra Packages For Enterprise Linux Graphicsmagick Graphicsmagick graphicsmagick |
|
| Weaknesses | CWE-787 | |
| CPEs | cpe:2.3:a:fedoraproject:extra_packages_for_enterprise_linux:8.0:*:*:*:*:*:*:* cpe:2.3:a:fedoraproject:extra_packages_for_enterprise_linux:9.0:*:*:*:*:*:*:* cpe:2.3:a:graphicsmagick:graphicsmagick:*:*:*:*:*:*:*:* cpe:2.3:o:debian:debian_linux:11:*:*:*:*:*:*:* cpe:2.3:o:debian:debian_linux:12:*:*:*:*:*:*:* cpe:2.3:o:debian:debian_linux:13:*:*:*:*:*:*:* |
|
| Vendors & Products |
Debian
Debian debian Linux Fedoraproject Fedoraproject extra Packages For Enterprise Linux Graphicsmagick Graphicsmagick graphicsmagick |
|
| References |
| |
| Metrics |
cvssV4_0
|
Status: PUBLISHED
Assigner: seal
Published:
Updated: 2026-08-20T12:56:01.246Z
Reserved: 2026-08-20T12:40:51.495Z
Link: CVE-2026-77118
No data.
Status : Received
Published: 2026-08-20T13:19:07.077
Modified: 2026-08-20T13:19:07.077
Link: CVE-2026-77118
No data.
OpenCVE Enrichment
Updated: 2026-08-21T12:09:24Z