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CVE-2026-49419

⚠️ high
🔍 Scan for this CVE
Summary

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 pani

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 Score
8.8
High
EPSS Score
0.3
Exploit Probability
Published Date
2026-08-19
First Seen: 2026-08-20
📊 Relative Risk Intelligence

This CVE is High Risk - more severe than 80.8% of all 364,849 vulnerabilities in our database.

#69,999
Top 25% most severe
Severity Percentile
🎯 CISA SSVC Assessment Updated: Aug 20, 2026
🔍 Exploitation Status
None
No known exploits
⚙️ Automatable
NO
Requires human interaction
💥 Technical Impact
Total
Complete system compromise possible
🏆 Discovered By
Yuxiang Yang, Yizhou Zhao, Ao Wang, Xuewei Feng, Qi Li, and Ke Xu from Tsinghua University using GLM-5.1 from Z.ai
SSVC data provided by CISA
Last Modified 2026-09-01
Source NVD 🔗
CVSS Vector 3.1 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CWE IDs (Weakness Types)
CWE-911

📦 Affected Products 2

Vendor Product Status Affected Versions
freebsd freebsd Affected
v15.0
freebsd freebsd Affected
v15.1

🔗 References 1

https://security.freebsd.org/advisories/FreeBSD-SA-2...
Vendor Advisory

🔗 Related CVEs 6

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These CVEs affect the same products