CVE-2026-71391

UNKNOWN 0.0

Off-by-One Error in GNU Emacs for Android

CVSS Score

0.0

EPSS Score

0.0%

EPSS Percentile

0th

GNU Emacs for Android contains an off-by-one error in the gvar table parser in src/sfnt.c. The shared-coordinate index boundary check in sfnt_vary_simple_glyph() and sfnt_vary_compound_glyph() uses a strict greater-than comparison instead of greater-than-or-equal, allowing a crafted TrueType variable font to bypass the check and trigger a heap-based out-of-bounds read via memcpy. An attacker can deliver a malicious font file via email, EWW (Emacs Web Wowser), or documents with custom faces, causing Emacs to load it. This exposes heap memory contents which can be later used to defeat ASLR. This issue was fixed in commit 95ab9ef627b212d74d321c5bbb5b56a1be7b9fbe

CWE	CWE-193
Vendor	gnu
Product	emacs
Published	Aug 10, 2026

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Affected Versions

GNU / Emacs

0 ≤ 30.2

References

NVD ↗ CVE.org ↗ EPSS Data ↗

cert.pl: https://cert.pl/en/posts/2026/08/CVE-2026-71391 gnu.org: https://www.gnu.org/savannah-checkouts/gnu/emacs/emacs.html git.savannah.gnu.org: https://git.savannah.gnu.org/cgit/emacs.git/commit/?id=95ab9ef627b212d74d321c5bbb5b56a1be7b9fbe

Credits

Michał Majchrowicz (AFINE Team) Marcin Wyczechowski (AFINE Team)