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Fencer Vulns
high 7.1

CVE-2026-77219 json

GNU Emacs < 31.0.91 Heap Over-Read via PBM/PPM/PGM Image Loader

published 2026-08-21 2 mo ago modified 2026-11-08 23 h ago also EUVD-2026-64138

cvss
7.1
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.1%
EPSS 0.1% chance of exploitation in 30 days, percentile 2%
public exploits
0
none known

Summary

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.

Patch / fix

  • GNU Emacs 31.0.91
  • emacs RHEL 10.2 1:29.4-14.el10_2.3
  • emacs-nw RHEL 10.2 1:29.4-14.el10_2.3
  • emacs-lucid RHEL 10.2 1:29.4-14.el10_2.3
  • emacs-common RHEL 10.2 1:29.4-14.el10_2.3
  • emacs-filesystem RHEL 10.2 1:29.4-14.el10_2.3
  • emacs RHEL 9 1:27.2-18.el9_8.2
  • emacs-nox RHEL 9 1:27.2-18.el9_8.2
  • emacs-lucid RHEL 9 1:27.2-18.el9_8.2

red hat advisories RHSA-2026:84591RHSA-2026:80507RHSA-2026:80506

  • emacs SLES for SAP 15 SP6, SLES for SAP 15 SP5, SLES for SAP 15 SP4 +9 more 27.2-150400.3.31.2
  • emacs SLES for SAP applications 16.0, SLES 16.0 30.2-160000.3.1
  • emacs SLES LTSS Extended Security 12 SP5, SLES 12 SP5-LTSS 24.3-25.26.1

suse advisories SUSE-SU-2026:4083-1SUSE-SU-2026:3993-1SUSE-SU-2026:23589-1

  • emacs openSUSE Leap 16.0 30.2-160000.3.1

opensuse advisories openSUSE-SU-2026:21711-1

  • emacs AlmaLinux 10 1:29.4-14.el10_2.3
  • emacs-nw AlmaLinux 10 1:29.4-14.el10_2.3
  • emacs-lucid AlmaLinux 10 1:29.4-14.el10_2.3
  • emacs-common AlmaLinux 10 1:29.4-14.el10_2.3
  • emacs-filesystem AlmaLinux 10 1:29.4-14.el10_2.3
  • emacs AlmaLinux 8 1:26.1-15.el8_10.2
  • emacs-nox AlmaLinux 8 1:26.1-15.el8_10.2
  • emacs-lucid AlmaLinux 8 1:26.1-15.el8_10.2

almalinux advisories ALSA-2026:84591ALSA-2026:80506ALSA-2026:80507

  • emacs Rocky Linux 10 1:29.4-14.el10_2.3
  • emacs Rocky Linux 9 1:27.2-18.el9_8.2
  • emacs Rocky Linux 8 1:26.1-15.el8_10.2

rocky linux advisories RLSA-2026:84591RLSA-2026:80507RLSA-2026:80506

  • emacs Azure Linux 3.0 29.4-6

azure linux advisories AZL-96986

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-77219 updated cvss 7.1

emacs: GNU Emacs: Heap over-read leading to information disclosure via crafted image

  • Red Hat Enterprise Linux 6 emacs, emacs-el, emacs-nox, emacs-common
    affected: workaround, no fix planned “To mitigate this issue, users should avoid opening or displaying untrusted PBM, PPM, or PGM image files within GNU Emacs. Exercise caution when handling image files from unknown or unverified sources.”
  • Red Hat Enterprise Linux 7 emacs, emacs-el, emacs-nox, emacs-common, emacs-terminal, emacs-filesystem
    affected: workaround, no fix available “To mitigate this issue, users should avoid opening or displaying untrusted PBM, PPM, or PGM image files within GNU Emacs. Exercise caution when handling image files from unknown or unverified sources.”
  • Red Hat Enterprise Linux AppStream (v. 8) emacs 26.1-15.el8_10.2, emacs-nox 26.1-15.el8_10.2, emacs-lucid 26.1-15.el8_10.2, emacs-common 26.1-15.el8_10.2, emacs-terminal 26.1-15.el8_10.2
    fixed: vendor fix “To mitigate this issue, users should avoid opening or displaying untrusted PBM, PPM, or PGM image files within GNU Emacs. Exercise caution when handling image files from unknown or unverified sources.” RHSA-2026:80506
  • Red Hat Enterprise Linux AppStream (v. 9) emacs 27.2-18.el9_8.2, emacs-nox 27.2-18.el9_8.2, emacs-lucid 27.2-18.el9_8.2, emacs-common 27.2-18.el9_8.2, emacs-filesystem 27.2-18.el9_8.2
    fixed: vendor fix “To mitigate this issue, users should avoid opening or displaying untrusted PBM, PPM, or PGM image files within GNU Emacs. Exercise caution when handling image files from unknown or unverified sources.” RHSA-2026:80507
  • Red Hat Enterprise Linux AppStream (v. 10) emacs 29.4-14.el10_2.3, emacs-nw 29.4-14.el10_2.3, emacs-lucid 29.4-14.el10_2.3, emacs-common 29.4-14.el10_2.3
    fixed: vendor fix “To mitigate this issue, users should avoid opening or displaying untrusted PBM, PPM, or PGM image files within GNU Emacs. Exercise caution when handling image files from unknown or unverified sources.” RHSA-2026:84591
  • Red Hat Enterprise Linux BaseOS (v. 8) emacs 26.1-15.el8_10.2, emacs-filesystem 26.1-15.el8_10.2
    fixed: vendor fix “To mitigate this issue, users should avoid opening or displaying untrusted PBM, PPM, or PGM image files within GNU Emacs. Exercise caution when handling image files from unknown or unverified sources.” RHSA-2026:80506
  • Red Hat Enterprise Linux BaseOS (v. 10) emacs 29.4-14.el10_2.3, emacs-filesystem 29.4-14.el10_2.3
    fixed: vendor fix “To mitigate this issue, users should avoid opening or displaying untrusted PBM, PPM, or PGM image files within GNU Emacs. Exercise caution when handling image files from unknown or unverified sources.” RHSA-2026:84591

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
2 mo ago

Exploit prediction

0.13% chance of exploitation in the next 30 days, higher than 2% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 4.0 6.9 CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:N/VA:H/SC:N/SI:N/SA:N
CNA 3.1 7.1 CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H
CNA 4.0 6.9 CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:N/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

Affected products

  • GNU Emacs

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.