CVE-2026-71392
Received Received - Intake

Integer Overflow in GNU Emacs for Android

Publication date: 2026-08-10

Last updated on: 2026-08-10

Assigner: CERT.PL

Description
GNU Emacs for Android is vulnerable to an integer overflow in the sfnt_read_cmap_format_12() function in src/sfnt.c. When processing a crafted TrueType font file, an unguarded addition in the xmalloc allocation call wraps around on 32-bit builds, causing a heap buffer overflow write. 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 results in heap memory corruption that can lead to code execution. This issue was fixed in commit c4e20777c26548722a37b03db93243e83a0d6188

CVSS Scores

EPSS Scores

Probability:
Percentile:

Meta Information

Published
2026-08-10
Last Modified
2026-08-10
Generated
2026-08-10
AI Q&A
2026-08-10
EPSS Evaluated
N/A
NVD
CVE-2026-71392
EUVD
EUVD-2026-55259

Affected Vendors & Products

Showing 3 associated CPEs
Vendor Product Version / Range
gnu emacs *
gnu emacs to 95ab9ef627b212d74d321c5bbb5b56a1be7b9fbe (inc)
gnu emacs to c4e20777c26548722a37b03db93243e83a0d6188 (inc)

Helpful Resources

Exploitability

CWE
CWE Icon
KEV
KEV Icon
CWE ID Description
CWE-190 The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.

Attack-Flow Graph

AI Quick Actions

Instant insights powered by AI
Executive Summary

GNU Emacs for Android has an integer overflow in the sfnt_read_cmap_format_12() function in src/sfnt.c. When processing a crafted TrueType font file, an unguarded addition in the xmalloc allocation call wraps around on 32-bit builds, causing a heap buffer overflow write. Attackers can deliver malicious font files via email, EWW, or documents with custom faces to trigger this issue.

Detection Guidance

This vulnerability involves a heap buffer overflow in GNU Emacs when processing crafted TrueType font files. Detection requires checking Emacs versions and analyzing font files for malicious content. No direct network detection commands are provided in the context.

Impact Analysis

This vulnerability can lead to heap memory corruption, potentially allowing code execution. An attacker could exploit it by sending a specially crafted font file, which when loaded by Emacs, could corrupt memory and enable arbitrary code execution on the affected system.

Compliance Impact

This vulnerability primarily involves memory corruption through heap buffer overflows triggered by malicious font files. While it does not directly impact GDPR or HIPAA compliance, such vulnerabilities could lead to unauthorized data access or code execution, potentially violating confidentiality requirements under these regulations if exploited.

Mitigation Strategies
  • Update GNU Emacs to the patched version that includes the fix in commit c4e20777c26548722a37b03db93243e83a0d6188.
  • Avoid opening untrusted font files or documents with custom faces in Emacs until patched.
  • Monitor for suspicious activity or crashes in Emacs when handling font files.

Chat Assistant

Ask questions about this CVE
Hi! I’m here to help you understand CVE-2026-71392. Ask me anything about the vulnerability, its impact, or mitigation strategies.
0/70

EPSS Chart