ZDI-26-784: FreeBSD Kernel kqueue Use-After-Free Local Privilege Escalation Vulnerability
ZDI disclosed FreeBSD kernel kqueue use-after-free CVE-2026-58093 allowing local privilege escalation.
The Zero Day Initiative published ZDI-26-784, a use-after-free vulnerability in the FreeBSD kernel kqueue implementation tracked as CVE-2026-58093. Local attackers who can execute low-privileged code can escalate privileges on affected installations. ZDI rated the issue CVSS 8.8. No in-the-wild exploitation is mentioned.
- ZDI-26-784 is a use-after-free in the FreeBSD kernel kqueue subsystem.
- CVE-2026-58093 is rated CVSS 8.8 and enables local privilege escalation.
- An attacker must already be able to run low-privileged code.
Vulnerabilities mentionedAll →
- CVE-2026-580937.0<1%The TIOCSCTTY ioctl handler drops the tty lock in order to acquire the process tree lockpublished · freebsd freebsd
| CVE | Vulnerability | CVSS | EPSS | Flags | Affected | Exposure | Published |
|---|---|---|---|---|---|---|---|
| CVE-2026-58093 | The TIOCSCTTY ioctl handler drops the tty lock in order to acquire the process tree lock The TIOCSCTTY ioctl handler drops the tty lock in order to acquire the process tree lock. After reacquiring the tty lock, the handler did not revalidate the state of the terminal, and could proceed to link a terminal that was concurrently being destroyed to the calling process' session. An unprivileged local user can exploit this race condition to escalate privileges. |
This vulnerability allows local attackers to escalate privileges on affected installations of FreeBSD Kernel. An attacker must first obtain the ability to execute low-privileged code on the target system in order to exploit this vulnerability. The ZDI has assigned a CVSS rating of 8.8. The following CVEs are assigned: CVE-2026-58093.
This source does not provide full text. Read it at zerodayinitiative.com.