CVE-2026-113869 Use-after-free in S/MIME decryption during a security device password prompt
- Exploited in the wild
- Not known
- Fix
- None listed
What is CVE-2026-113869?
CVE-2026-113869 is a medium-severity vulnerability in Mozilla Thunderbird, published on 20 Oct 2026.
Official description
When Thunderbird asked for a security device password (for example a smartcard PIN or the Primary Password) while decrypting an S/MIME message, the message load could finish or be cancelled while the prompt was open. This freed the message decoder while it was still in use, causing a use-after-free and a potentially exploitable crash. This vulnerability was fixed in Thunderbird 158.0.1 and Thunderbird 153.6.
Weakness: CWE-416
Which versions are affected by CVE-2026-113869?
How do I fix CVE-2026-113869?
No fix has been published for CVE-2026-113869 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-113869 being exploited?
There is no known exploitation of CVE-2026-113869 in the wild and no public exploit code.
Sources
Also known as GHSA-2xmq-c4ch-m4cp, UBUNTU-CVE-2026-113869.