FreeBSD Kqueue privileges management

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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8.8$0-$5k2.56

Summaryinfo

A vulnerability was found in FreeBSD Kqueue. It has been declared as very critical. Affected is an unknown function. Executing a manipulation can lead to privileges management. This vulnerability is handled as CVE-2026-58099. It is possible to launch the attack on the local host. There is not any exploit available.

Detailsinfo

A vulnerability was found in FreeBSD Kqueue (version now known). It has been declared as very critical. This vulnerability affects some unknown processing. The manipulation with an unknown input leads to a privileges management vulnerability. The CWE definition for the vulnerability is CWE-269. The product does not properly assign, modify, track, or check privileges for an actor, creating an unintended sphere of control for that actor. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

When copying knotes from a parent kqueue to a child, the copy code did not correctly exclude marker knotes (used internally to track list traversal position) before marking them as in-flux and releasing the kqueue lock. If another thread freed a marker while the lock was dropped, the subsequent in-flux decrement operated on freed memory. An unprivileged local user may be able to exploit these races to escalate privileges.

The advisory is shared for download at security.freebsd.org. This vulnerability was named CVE-2026-58099 since 06/29/2026. The exploitation appears to be easy. The attack needs to be approached locally. There are neither technical details nor an exploit publicly available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 10/15/2026). The MITRE ATT&CK project declares the attack technique as T1068.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Type

Vendor

Name

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

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

VulDB Base Score: 8.8
VulDB Temp Score: 8.8
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: Privileges management
CWE: CWE-269 / CWE-266
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: No

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔒

Timelineinfo

06/29/2026 CVE reserved
10/15/2026 +108 days Advisory disclosed
10/15/2026 +0 days VulDB entry created
10/15/2026 +0 days VulDB entry last update

Sourcesinfo

Advisory: security.freebsd.org
Status: Confirmed

CVE: CVE-2026-58099 (🔒)
GCVE (CVE): GCVE-0-2026-58099
GCVE (VulDB): GCVE-100-420496

Entryinfo

Created: 10/15/2026 08:49
Changes: 10/15/2026 08:49 (51)
Complete: 🔍
Cache ID: 216::103

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