ZDI-26-785: FreeBSD Kernel Shared Memory Time-Of-Check Time-Of-Use Local Privilege Escalation Vulnerability
ZDI disclosed FreeBSD kernel shared-memory TOCTOU bug CVE-2026-58094 enabling local privilege escalation.
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CVE-2026-58094
- CVSS 3.1
- 7.8 high
- EPSS
- <1%p1
- Published
- ·
- Modified
Description · NVD
The FIOSSHMLPGCNF ioctl(2) operation configures the page size for a largepage shared memory object. This is intended to be used immediately after creating the object, before any memory is allocated for the object. The handler checked whether a page size had already been configured without holding the rangelock. Two concurrent callers could both observe an unconfigured object and set conflicting page sizes, leaving the object in an inconsistent state. An unprivileged local user can exploit this race to escalate privileges.