CVE-2026-49419: When the JAIL_AT_DESC flag is specified, kern_jail_set() and kern_jail_get() released the reference to the caller's…
CVE-2026-49419 · Severity: high · CVSS 8.8 · Published 2026-08-19
When the JAIL_AT_DESC flag is specified, kern_jail_set() and kern_jail_get() released the reference to the caller's current prison before looking up the jail descriptor. If the descriptor lookup failed, error-handling paths released the same reference a second time.
An unprivileged local user can trigger a prison reference count underflow, which may cause the prison structure to be freed while still in use. When this is done on the jail host, the bug will generally result in an immediate panic. However, if the user is running in a jail, then it may be possible to exploit the bug to elevate privileges.
No. Junglewise Threat Intelligence has no report of CVE-2026-49419 being exploited in the wild.
How severe is CVE-2026-49419?
High severity, with a CVSS score of 8.8, published 19 August 2026.
Which products and versions are affected?
Freebsd. The advisory does not name versions.
Is there a fix for CVE-2026-49419?
No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
Am I affected by CVE-2026-49419?
Check whether you run Freebsd. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.