CVE-2026-77118 (GCVE-0-2026-77118)
Vulnerability from cvelistv5 – Published: 2026-08-20 12:42 – Updated: 2026-08-20 12:56
VLAI
EPSS
VEX
Title
Out-of-bounds write in GraphicsMagick PCD decoder
Summary
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.
Severity
CWE
- CWE-787 - Out-of-bounds write
Assigner
References
2 references
| URL | Tags |
|---|---|
| https://foss.heptapod.net/graphicsmagick/graphics… | patch |
| https://foss.heptapod.net/graphicsmagick/graphics… | release-notes |
Impacted products
3 products
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| GraphicsMagick Group | GraphicsMagick |
Affected:
1.0.0 , < 1.3.48
(semver)
cpe:2.3:a:graphicsmagick:graphicsmagick:*:*:*:*:*:*:*:* |
||
| Debian | graphicsmagick |
Affected:
0 , < 1.4+really1.3.48-1
(deb)
cpe:2.3:o:debian:debian_linux:11:*:*:*:*:*:*:* cpe:2.3:o:debian:debian_linux:12:*:*:*:*:*:*:* cpe:2.3:o:debian:debian_linux:13:*:*:*:*:*:*:* |
||
| Fedora Project | GraphicsMagick |
Affected:
0 , < 1.3.48
(rpm)
cpe:2.3:a:fedoraproject:extra_packages_for_enterprise_linux:8.0:*:*:*:*:*:*:* cpe:2.3:a:fedoraproject:extra_packages_for_enterprise_linux:9.0:*:*:*:*:*:*:* |
Date Public
2026-08-20 09:43
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"redhat_vex": {
"current_release_date": "2026-08-22T12:09:01+00:00",
"cve": "CVE-2026-77118",
"id": "CVE-2026-77118",
"initial_release_date": "2026-08-20T12:42:42.952000+00:00",
"product_status:known_not_affected": "1",
"source": "Red Hat CSAF VEX",
"status": "final",
"title": "GraphicsMagick: GraphicsMagick: Arbitrary code execution via crafted PCD file",
"url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-77118.json",
"version": "3"
}
}
}
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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
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