CVE-2026-71391

Off-by-One Error in GNU Emacs for Android

MEDIUM
5.3
CVSS Score
Published: August 10, 2026 at 10:22 AM UTC
Updated: October 24, 2026 at 03:10 PM UTC
1 product affected across 1 vendorEmacs

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Severity
MEDIUM5.3
Exploit prediction
EPSS 0.5%
SSVC
No known exploit

Description

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

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

0 ≤ v ≤ 30.20

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

5.3MEDIUMCERT-PL
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-193

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