Skip to main content
VulnerabilityPublished Updated

CVE-2026-58099: FreeBSD · Race Condition

Affects FreeBSDSource CVE Database V5

0

Not known to be exploited · CVSS 7.0 High : upgrade to p4 soon.

Data as of 26 Oct 2026, 17:16 UTC

CVSS 3.1 base score
7.0High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.1% chance of exploitation in 30 days – higher than 0% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CISA SSVC
Exploitation
No evidence of active exploitation and no public proof of concept
Automatable
Attackers cannot reliably automate steps 1–4 of the kill chain
Technical impact
Total control over the software or total information disclosure

CISA SSVC assessment, 2026-10-16.

Patch
Available – fixed in p4
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 15 Oct 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

Upgrade FreeBSD to p4.

Affected software

ProductAffectedFixed in
FreeBSDFreeBSDAffected
  • >=15.1-RELEASE <p4
Fixed in
  • p4

AI-suggested

A fix is available in FreeBSD patch level p4. Users should upgrade to p4 or later to remediate this vulnerability. No additional mitigation actions are indicated beyond applying the official patch.

Description

CVE-2026-58099 is a race condition vulnerability in FreeBSD affecting the copying of knotes from a parent kqueue to a child. The flaw arises because marker knotes, which track list traversal positions internally, were not properly excluded before being marked as in-flux and releasing the kqueue lock. This can lead to use-after-free conditions if another thread frees a marker while the lock is dropped. An unprivileged local user could exploit this to escalate privileges on the system.

References

Community reviews

Loading reviews…