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Vulnerability record · CVE-2026-49419 · published 19 August 2026

CVE-2026-49419: Freebsd vulnerability

Freebsd · Freebsd

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.

8.8 CVSS 3.1 High EPSS 0.47% · top 62.2% CWE-911 · CWE-911
8.8CVSS 3.1 base score
0.47%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
1References
1 Sep 2026Last modified by NVD

Description

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:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://security.freebsd.org/advisories/FreeBSD-SA-26:38.jail.asc Vendor Advisory

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Same products first, then exploited flaws of the same weakness class.

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Source: NIST National Vulnerability Database (record CVE-2026-49419), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.