CVE-2026-71392 Integer Overflow in GNU Emacs for Android
An integer overflow in GNU Emacs for Android allows attackers to execute arbitrary code via a crafted TrueType font file.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-71392?
CVE-2026-71392 is a medium-severity vulnerability in GNU Emacs, published on 10 Aug 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official 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
Weakness: CWE-190
Which versions are affected by CVE-2026-71392?
How do I fix CVE-2026-71392?
No fix has been published for CVE-2026-71392 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-71392 being exploited?
There is no known exploitation of CVE-2026-71392 in the wild and no public exploit code.
Sources
Also known as GHSA-39p3-jw8m-jmr7, UBUNTU-CVE-2026-71392.