CVE-2026-77219
GNU Emacs < 31.0.91 Heap Over-Read via PBM/PPM/PGM Image Loader
Description
GNU Emacs before 31.0.91 contains an integer overflow in the PBM/PPM/PGM image loader that allows an attacker to leak heap memory contents by supplying a crafted image with large dimensions and an elevated max color index. The image loader multiplies image dimensions and channel count using signed integer arithmetic; for sufficiently large values, the result wraps to a negative number, bypassing the bounds check and causing the pixel reader to access heap memory past the end of the allocated buffer. The over-read contents are interpreted as pixel color values and rendered on screen.
CVSS Vector Breakdown
AV:LAttack VectorAC:LAttack ComplexityPR:NPrivileges RequiredUI:RUser InteractionS:UScopeC:HConfidentialityI:NIntegrityA:HAvailabilityWeaknesses
Affected Products
Exploitability
Attack Graph
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MITRE ATT&CK
2 techniquesReferences
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