CVE-2026-89643
CVE-2026-89643 is a security vulnerability. O3 Security confirms whether CVE-2026-89643 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
In the Linux kernel, the following vulnerability has been resolved: audit: avoid dropping live tree ref on fsnotify rule autoremove audit_del_rule() is used for both netlink deletion…
Description
In the Linux kernel, the following vulnerability has been resolved:
audit: avoid dropping live tree ref on fsnotify rule autoremove
audit_del_rule() is used for both netlink deletion templates and internal fsnotify autoremove. The former passes a parsed template which owns a temporary tree reference; the latter passes the installed entry itself.
The unconditional audit_put_tree() at the end of audit_del_rule() assumes the template case. For mixed AUDIT_DIR plus AUDIT_EXE rules, an fsnotify autoremove event therefore drops the installed rule's live tree reference. Repeating this across rules sharing the same tree can free the tree while another rule still references it, and a later autoremove dereferences the freed pathname while comparing rules.
Move the temporary-tree put to audit_rule_change(), the caller that owns deletion templates. Keep it in the AUDIT_DEL_RULE cleanup so both successful deletion and -ENOENT still release the parser-owned tree.
[PM: dropped unnecessary comment for line length reasons]
Detection & mitigation playbook
VulnerabilityDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for the affected component. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Remediation status
No patched version of the affected component has shipped for CVE-2026-89643 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-89643 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-89643. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-89643 in your dependencies?
O3 detects CVE-2026-89643 across dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.