CVE-2026-58099
Memory safety bugs in kqueue copy-on-fork implementation
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.
Attack profile
How easy it is to exploit
- Attack vector
- Local
- Complexity
- High
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
Memory safety bugs in kqueue copy-on-fork implementation
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.
- Record
CVE-2026-58099- CVSS 3.1
- 7.0 High
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-362, CWE-416
- Updated
- 2026-11-02
EUVDEUVD-2026-101856
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.
- Record
EUVD-2026-101856- CVSS 3.1
- 7.0 High
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-f53j-rp59-76p7
When copying knotes from a parent kqueue to a child, the copy code did not correctly exclude...
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.
- Record
GHSA-f53j-rp59-76p7- CVSS 3.1
- 7.0 High
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-362
- Updated
- 2026-11-02
NVD
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.
- Record
CVE-2026-58099- CVSS 3.1
- 7.0 High
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-362, CWE-416
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-58099 is a high vulnerability (CVSS 7.0) in Freebsd, published October 15, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.10%, the 0th percentile. No source names a fixed version.