FreeBSD up to p0.x/p10 Jail kern_jail_set/kern_jail_get use after free

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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8.4$0-$5k0.86-

Summaryinfo

A vulnerability classified as very critical has been found in FreeBSD up to p0.x/p10. This impacts the function kern_jail_set/kern_jail_get of the component Jail. This manipulation causes use after free. This vulnerability is tracked as CVE-2026-49419. The attack is restricted to local execution. No exploit exists.

Detailsinfo

A vulnerability classified as very critical was found in FreeBSD up to p0.x/p10. Affected by this vulnerability is the function kern_jail_set/kern_jail_get of the component Jail. The manipulation with an unknown input leads to a use after free vulnerability. The CWE definition for the vulnerability is CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

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.

The advisory is shared at security.freebsd.org. This vulnerability is known as CVE-2026-49419 since 05/29/2026. The exploitation appears to be easy. An attack has to be approached locally. Technical details are known, but no exploit is available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 08/19/2026).

Upgrading to version p1 or p11 eliminates this vulnerability.

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Type

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 8.8
VulDB Meta Temp Score: 8.4

VulDB Base Score: 8.8
VulDB Temp Score: 8.4
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Use after free
CWE: CWE-416 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: No

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: FreeBSD p1/p11

Timelineinfo

05/29/2026 CVE reserved
08/19/2026 +82 days Advisory disclosed
08/19/2026 +0 days VulDB entry created
08/19/2026 +0 days VulDB entry last update

Sourcesinfo

Product: freebsd.org

Advisory: security.freebsd.org
Status: Confirmed

CVE: CVE-2026-49419 (🔒)
GCVE (CVE): GCVE-0-2026-49419
GCVE (VulDB): GCVE-100-392797

Entryinfo

Created: 08/19/2026 06:58
Changes: 08/19/2026 06:58 (55)
Complete: 🔍
Cache ID: 216::103

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