CVE-2026-77118
Out-of-bounds write in GraphicsMagick PCD decoder
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.
INFO
Published Date :
Aug. 20, 2026, 1:19 p.m.
Last Modified :
Aug. 20, 2026, 1:19 p.m.
Remotely Exploit :
No
Source :
22e2d327-25fe-45d7-9f0c-dcd23b7108df
Affected Products
The following products are affected by CVE-2026-77118
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 4.0 | HIGH | 22e2d327-25fe-45d7-9f0c-dcd23b7108df | ||||
| CVSS 4.0 | HIGH | 22e2d327-25fe-45d7-9f0c-dcd23b7108df |
Solution
- Update GraphicsMagick to the latest version.
- Apply any available patches for older versions.
- Avoid processing untrusted PCD files.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-77118.
| URL | Resource |
|---|---|
| https://foss.heptapod.net/graphicsmagick/graphicsmagick/-/commit/937cdd9920bd96 | |
| https://foss.heptapod.net/graphicsmagick/graphicsmagick/-/raw/GraphicsMagick-1_3_48/ChangeLog |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-77118 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-77118
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-77118 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-77118 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by 22e2d327-25fe-45d7-9f0c-dcd23b7108df
Aug. 20, 2026
Action Type Old Value New Value Added Affected [{'cpes': ['cpe:2.3:a:graphicsmagick:graphicsmagick:*:*:*:*:*:*:*:*'], 'repo': 'https://foss.heptapod.net/graphicsmagick/graphicsmagick', 'vendor': 'GraphicsMagick Group', 'modules': ['PCD / PCDS image coder'], 'product': 'GraphicsMagick', 'versions': [{'status': 'affected', 'version': '1.0.0', 'lessThan': '1.3.48', 'versionType': 'semver'}], 'platforms': ['Linux', 'Windows', 'macOS'], 'programFiles': ['coders/pcd.c'], 'defaultStatus': 'unaffected', 'programRoutines': [{'name': 'DecodeImage'}]}, {'cpes': ['cpe:2.3:o:debian:debian_linux:11:*:*:*:*:*:*:*', 'cpe:2.3:o:debian:debian_linux:12:*:*:*:*:*:*:*', 'cpe:2.3:o:debian:debian_linux:13:*:*:*:*:*:*:*'], 'vendor': 'Debian', 'product': 'graphicsmagick', 'versions': [{'status': 'affected', 'version': '0', 'lessThan': '1.4+really1.3.48-1', 'versionType': 'deb'}], 'packageName': 'graphicsmagick', 'collectionURL': 'https://packages.debian.org', 'defaultStatus': 'unaffected'}, {'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:*:*:*:*:*:*:*'], 'vendor': 'Fedora Project', 'product': 'GraphicsMagick', 'versions': [{'status': 'affected', 'version': '0', 'lessThan': '1.3.48', 'versionType': 'rpm'}], 'packageName': 'GraphicsMagick', 'collectionURL': 'https://dl.fedoraproject.org/pub/epel', 'defaultStatus': 'unaffected'}] 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. Added CVSS V4.0 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 Added CWE CWE-787 Added Reference https://foss.heptapod.net/graphicsmagick/graphicsmagick/-/commit/937cdd9920bd96 Added Reference https://foss.heptapod.net/graphicsmagick/graphicsmagick/-/raw/GraphicsMagick-1_3_48/ChangeLog