CVE-2026-89500
CVE-2026-89500 is a security vulnerability. O3 Security confirms whether CVE-2026-89500 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: ring-buffer: Make cpu_buffer::free_page a buffer_data_read_page Discarding a cached reader page after a concurrent…
Description
In the Linux kernel, the following vulnerability has been resolved:
ring-buffer: Make cpu_buffer::free_page a buffer_data_read_page
Discarding a cached reader page after a concurrent ring buffer resize uses the new global subbuf_order for the free_pages() call. This mismatched order may crashes the kernel or leaks memory because the cached page was allocated under the old size.
Save the actual free_page order alongside the page address to ensure we always refer to the correct value and do not rely on the potentially stalled cpu_buffer->subbuf_order value. The simplest is to make free_page a buffer_data_read_page which already covers exactly what we need: a page address and a page order.
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-2026-89500 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-2026-89500 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-2026-89500. 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-2026-89500 in your dependencies?
O3 detects CVE-2026-89500 across dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.