CVE-2026-71393: gnu emacs Integer Overflow or Wraparound

Vulnerability summary

CVE-2026-71393 is a medium (CVSS 5.3) Integer Overflow or Wraparound vulnerability in gnu emacs. EPSS estimates a 0.67% chance of exploitation in the next 30 days, higher than 51.2% of scored vulnerabilities.

Timeline

1. 10-08-2026
   PublishedVulnerability first disclosed.
2. 10-08-2026
   Last modifiedVulnerability information updated.

Description

GNU Emacs for Android is vulnerable to an integer overflow in sfnt_read_name_table() in src/sfnt.c. The function computes an allocation size using a 32-bit length value from a TrueType font file without overflow checking. On 32-bit targets, a crafted font causes the calculation to wrap, resulting in an undersized heap allocation. A subsequent read() call writes beyond the buffer, causing a heap buffer overflow. 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 can lead to heap memory corruption and potential code execution. This issue was fixed in commit d51a4722316efe0960994d371e1859099894d1ca

• CWE-190Integer Overflow or WraparoundThe 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.