CVE-2026-49419
CVE-2026-49419 is a high-severity vulnerability in Freebsd with a CVSS 3.x base score of 8.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-911.
Key facts
- Severity: High (CVSS 3.x base score 8.8)
- EPSS exploit prediction: 0% (38th percentile)
- Actively exploited: Not listed in CISA KEV
- Weakness: CWE-911
- Affected product: Freebsd
- Published:
- Last modified:
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.
Frequently asked questions
- What is 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 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.
- How severe is CVE-2026-49419?
- CVE-2026-49419 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
- Is CVE-2026-49419 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (38th percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2026-49419?
- CVE-2026-49419 primarily affects Freebsd. In total, 14 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
- How do I fix CVE-2026-49419?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
- When was CVE-2026-49419 published?
- CVE-2026-49419 was published on 2026-08-19 and last updated on 2026-09-01.
References
Affected products (14)
- cpe:2.3:o:freebsd:freebsd:15.0:-:*:*:*:*:*:*
- cpe:2.3:o:freebsd:freebsd:15.0:p1:*:*:*:*:*:*
- cpe:2.3:o:freebsd:freebsd:15.0:p10:*:*:*:*:*:*
- cpe:2.3:o:freebsd:freebsd:15.0:p2:*:*:*:*:*:*
- cpe:2.3:o:freebsd:freebsd:15.0:p3:*:*:*:*:*:*
- cpe:2.3:o:freebsd:freebsd:15.0:p4:*:*:*:*:*:*
- cpe:2.3:o:freebsd:freebsd:15.0:p5:*:*:*:*:*:*
- cpe:2.3:o:freebsd:freebsd:15.0:p6:*:*:*:*:*:*
- cpe:2.3:o:freebsd:freebsd:15.0:p7:*:*:*:*:*:*
- cpe:2.3:o:freebsd:freebsd:15.0:p8:*:*:*:*:*:*
- cpe:2.3:o:freebsd:freebsd:15.0:p9:*:*:*:*:*:*
- cpe:2.3:o:freebsd:freebsd:15.1:-:*:*:*:*:*:*
- cpe:2.3:o:freebsd:freebsd:15.1:rc2:*:*:*:*:*:*
- cpe:2.3:o:freebsd:freebsd:15.1:rc3-p1:*:*:*:*:*:*
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