CVE-2026-77219
GNU Emacs < 31.0.91 Heap Over-Read via PBM/PPM/PGM Image Loader
CVSS Score
7.1
EPSS Score
0.0%
EPSS Percentile
0th
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.
| CWE | CWE-190 CWE-125 |
| Vendor | gnu |
| Product | emacs |
| Published | Aug 21, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H Attack Vector
Local
Attack Complexity
Low
Privileges Required
None
User Interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
High
Affected Versions
GNU / Emacs
0 < 31.0.91
References
debbugs.gnu.org: https://debbugs.gnu.org/cgi/bugreport.cgi?bug=81344 github.com: https://github.com/emacs-mirror/emacs/releases/tag/emacs-31.0.91 github.com: https://github.com/emacs-mirror/emacs/commit/b07e634e4cf45162ae0178e32092b040587f2c6c vulncheck.com: https://www.vulncheck.com/advisories/gnu-emacs-heap-over-read-via-pbm-ppm-pgm-image-loader
Credits
Tristan Madani