CVE-2026-24881
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (1.68%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 3.1
- 9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 1.68% probability · 76th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-121
- Affected
- gnupg/gnupg · gpg4win/gpg4win
- Source
- cve@mitre.org
References
- https://dev.gnupg.org/T8044Exploit, Product
- https://www.openwall.com/lists/oss-security/2026/01/27/8Mailing List, Third Party Advisory
- https://access.redhat.com/security/cve/CVE-2026-24881
- https://bugzilla.redhat.com/show_bug.cgi?id=2433480
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-24881.json
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.