CVE-2026-71392
Integer Overflow in GNU Emacs for Android
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
INFO
Published Date :
Aug. 10, 2026, 11:17 a.m.
Last Modified :
Aug. 10, 2026, 11:17 a.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 4.0 | MEDIUM | 4bb8329e-dd38-46c1-aafb-9bf32bcb93c6 | ||||
| CVSS 4.0 | MEDIUM | [email protected] |
Solution
- Update GNU Emacs to include the fix.
- Apply commit c4e20777c26548722a37b03db93243e83a0d6188.
- Avoid processing untrusted font files.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-71392.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-71392 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-71392
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-71392 vulnerability anywhere in the article.
-
cert.pl
Vulnerabilities in GNU Emacs software
Vulnerabilities in GNU Emacs software CVE ID CVE-2026-71391 Publication date 10 August 2026 Vendor GNU Product Emacs Vulnerable versions All through 30.2 Vulnerability type (CWE) Off-by-one Error (CWE ... Read more
The following table lists the changes that have been made to the
CVE-2026-71392 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by [email protected]
Aug. 10, 2026
Action Type Old Value New Value Added Affected [{'repo': 'https://cgit.git.savannah.gnu.org/cgit/emacs.git', 'vendor': 'GNU', 'product': 'Emacs', 'versions': [{'status': 'affected', 'changes': [{'at': 'commit c4e20777c26548722a37b03db93243e83a0d6188', 'status': 'unaffected'}], 'version': '0', 'versionType': 'custom', 'lessThanOrEqual': '30.2'}], 'platforms': ['Android', '32 bit'], 'programFiles': ['src/sfnt.c'], 'defaultStatus': 'unaffected'}] Added 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 Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:L/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 Added CWE CWE-190 Added Reference https://cert.pl/en/posts/2026/08/CVE-2026-71391 Added Reference https://git.savannah.gnu.org/cgit/emacs.git/commit/?id=c4e20777c26548722a37b03db93243e83a0d6188 Added Reference https://www.gnu.org/savannah-checkouts/gnu/emacs/emacs.html