CVE-2026-49419: FreeBSD · Improper Update of Reference Count
Affects FreeBSDSource GCVE Database
Not known to be exploited · CVSS 8.8 High.
Data as of 5 Nov 2026, 21:32 UTC
Thin evidence
One scorer or none| CISA-ADP | CVSS 3.1 | 8.8 |
|---|
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 19 Aug 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 5 Nov 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| FreeBSD FreeBSD | Affected
| Fixed in– |
AI-suggested
Until a fix is available, restrict unprivileged local user access to the jail subsystem and monitor for unusual system behavior. Avoid running untrusted code within jails on affected versions.
Description
CVE-2026-49419 is a vulnerability in FreeBSD versions 15.0-RELEASE and 15.1-RELEASE involving improper update of a reference count in the jail subsystem. Specifically, when the JAIL_AT_DESC flag is used, kern_jail_set() and kern_jail_get() functions release a reference to the current prison before looking up the jail descriptor, and if the lookup fails, the reference is released a second time. This causes a reference count underflow, potentially freeing the prison structure while still in use. On the jail host, this typically causes a system panic, but within a jail, it may allow privilege escalation by an unprivileged local user.