CVE-2026-49419Jail reference count underflow
Updated under an hour ago ()
Does this affect you?
It affects FreeBSD. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
Do this next
Free account, 1 product
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.
- CVSS
- 8.8 HIGH (v3.1, CISA ADP)CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Weakness (CWE)
- CWE-911
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- freebsd
- NVD analysis
- Analyzed
- Record last updated
- Aug 20, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
FreeBSD FreeBSD freebsd:freebsd (from the name) | from 15.1-RELEASE before p1; from 15.0-RELEASE before p11 | CNA record |
freebsd freebsd freebsd:freebsd | 15.0; 15.0; 15.0; 15.0; 15.0; 15.0; 15.0; 15.0; and 6 more ranges | NVD |
References
- https://security.freebsd.org/advisories/FreeBSD-SA-26:38.jail.ascvendor-advisory
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.