Dashboard / CVE-2026-77118

CVE-2026-77118

HIGH
MEDIUM Priority: 0.01 BB Relevance: 42/100
Published: 2026-08-20 Modified: 2026-10-27 First seen: 2026-10-29 Status: active

Attack Surface

Low Complexity No Auth Conf. Impact Integ. Impact

CVSS Vector Breakdown

AV: Local
AC: Low
PR: None
UI: Active
S: X
AT: None
VC: High
VI: High
VA: High

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.

Weakness Classification (1)

References & Advisories (2)

Bug Bounty Relevance

42 / 100
✓ No authentication
✓ Low complexity

CVSS Score

8.4 / 10.0 v4.0
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

EPSS — Exploitation Probability

0.17%
Raw Score 0.001710
Percentile 6.5%
Date 2026-10-29

EPSS Trend

2026-10-29
0.00171
2026-10-28
0.00171

Intelligence Sources

nvd ref →

External Links