CVE-2026-80718
CVE-2026-80718 is a remote code execution vulnerability. O3 Security confirms whether CVE-2026-80718 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: mm/percpu-km: fix bitmap overflow and accounting in pcpu_create_chunk() In pcpu_create_chunk(), nr_pages is the…
Description
In the Linux kernel, the following vulnerability has been resolved:
mm/percpu-km: fix bitmap overflow and accounting in pcpu_create_chunk()
In pcpu_create_chunk(), nr_pages is the total contiguous backing allocation, i.e., nr_units * pcpu_unit_pages, but pcpu_chunk_populated() uses it to set chunk->populated, whose size is pcpu_unit_pages, bitmap. Since bit N in chunk->populated means page offset N inside every unit is backed. When nr_units > 1, the function writes beyond chunk->populated. Fix it by using chunk->nr_pages.
It also fixes the global pcpu_nr_empty_pop_pages accounting, since pcpu_balance_free() only iterates up to chunk->nr_pages.
Commit a63d4ac4ab609 ("percpu: make percpu-km set chunk->populated bitmap properly") introduced the bitmap overflow issue. Later, commit b539b87fed37f ("percpu: implmeent pcpu_nr_empty_pop_pages and chunk->nr_populated") added pcpu_nr_empty_pop_pages and caused the accounting issue.
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-2026-80718 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-2026-80718 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-2026-80718. 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-2026-80718 in your dependencies?
O3 detects CVE-2026-80718 across dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.