CVE-2026-24881: gnupg Stack-based Buffer Overflow

Vulnerability summary

CVE-2026-24881 is a critical (CVSS 9.8) Stack-based Buffer Overflow vulnerability in gnupg. EPSS estimates a 1.84% chance of exploitation in the next 30 days, higher than 78.6% of scored vulnerabilities. 1 public exploit is recorded.

Timeline

1. 27-01-2026
   PublishedVulnerability first disclosed.
2. 15-07-2026
   Last modifiedVulnerability information updated.

Description

In GnuPG before 2.5.17, a crafted CMS (S/MIME) EnvelopedData message carrying an oversized wrapped session key can cause a stack-based buffer overflow in gpg-agent during PKDECRYPT--kem=CMS handling. This can easily be leveraged for denial of service; however, there is also memory corruption that could lead to remote code execution.

• CWE-121Stack-based Buffer OverflowA stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function).