CVE-2026-77118

HIGHPre-NVD 8.48.4
EchelonGraph scoreLOW confidence

This high-severity CVE scores 8.4 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit-prediction score not yet available (the EPSS model rescores nightly; freshly-published CVEs typically appear within 48 hours). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: secondary
Trending — 3 sources updated this week
8.4EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: —CVSS: 8.4Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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.

CVSS v3
8.4
EG Score
8.4(low)
EG Risk
42(Track)
EG Risk 42/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity84% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
—
EPSS %ILE
—
KEV
Not listed

Published

August 20, 2026

Last Modified

August 20, 2026

Advisory Details (2)

Auto-updated Aug 20, 2026
No patch confirmed yet.
generic
https://foss.heptapod.net/graphicsmagick/graphicsmagick/-/raw/GraphicsMagick-1_3_48/ChangeLog
generic

coders/pcd.c (ReadPCDImage): Over-provision the per-channel Huffman decode... (937cdd9920bd) · Commits · GraphicsMagick / graphicsmagick · GitLab

https://foss.heptapod.net/graphicsmagick/graphicsmagick/-/commit/937cdd9920bd96

Vendor Advisories for CVE-2026-77118(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 4× in last 7d / 4× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-08-21 00:16 UTCGHSA enrichment
  2. 2026-08-20 13:23 UTCEG score recompute
  3. 2026-08-20 13:08 UTCEG score recompute
  4. 2026-08-20 13:06 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(4)

What is CVE-2026-77118?
CVE-2026-77118 is a high vulnerability published on August 20, 2026. 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…
When was CVE-2026-77118 disclosed?
CVE-2026-77118 was first published in the National Vulnerability Database on August 20, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
What is the CVSS score of CVE-2026-77118?
CVE-2026-77118 has a CVSS v3 base score of 8.4 (NVD). The EG score is currently aggregating — additional source signals are being incorporated as they become available..
How do I remediate CVE-2026-77118?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-77118, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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