CVE-2026-43863 Denial of service in mutt
An attacker can cause a denial of service in the Mutt email client by triggering an infinite loop during GPG cryptographic operations.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-43863?
CVE-2026-43863 is a low-severity denial of service vulnerability in mutt, published on 4 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
mutt before 2.3.2 has an infinite loop in data_object_to_stream in crypt-gpgme.c.
Weakness: CWE-253
Which versions are affected by CVE-2026-43863?
How do I fix CVE-2026-43863?
Upgrade to a fixed version.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-43863 being exploited?
There is no known exploitation of CVE-2026-43863 in the wild and no public exploit code.
Sources
Also known as AZL-85590, DEBIAN-CVE-2026-43863, GHSA-g7m5-w98f-vqg2, UBUNTU-CVE-2026-43863.