How severe is CVE-2026-80670?

CVE-2026-80670 has a CVSS score of 9.1/10, rated CRITICAL. Immediate patching is strongly recommended.

Which packages are affected by CVE-2026-80670?

CVE-2026-80670 affects the following packages: Kernel (Linux). Ecosystems affected: Linux.

How do I fix CVE-2026-80670?

Update Kernel to 6.18.40 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-80670 is resolved across your whole dependency graph.

How do I detect CVE-2026-80670 in my Linux dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Kernel. 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.

How do I mitigate CVE-2026-80670 if there is no patch (or I can't update yet)?

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 does O3 Security protect against CVE-2026-80670?

O3 pinpoints whether CVE-2026-80670 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is CVE-2026-80670 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-80670 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

When was CVE-2026-80670 published, and has it been updated?

CVE-2026-80670 was published on August 28, 2026 and was last updated on August 30, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐧

🐧 Linux

Not in CISA KEV

CRITICAL severity

CVE-2026-80670

CRITICAL

CVE-2026-80670 is a critical-severity (CVSS 9.1) vulnerability in Kernel. O3 Security confirms whether CVE-2026-80670 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.

perf tools: Use perf_env__get_cpu_topology() in machine__resolve()

Published

Aug 28, 2026

Updated

Aug 30, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Aug 30, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Real-World Exposure

1 pkg affected

🐧Kernel

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Linux packages — download data is not available via public APIs for these ecosystems.

Description

In the Linux kernel, the following vulnerability has been resolved:

perf tools: Use perf_env__get_cpu_topology() in machine__resolve()

machine__resolve() accesses env->cpu[al->cpu].socket_id after checking al->cpu >= 0 and env->cpu != NULL, but without validating al->cpu against env->nr_cpus_avail. Since al->cpu comes from the untrusted perf.data sample, a crafted file with a large CPU index causes an out-of-bounds heap read.

Use perf_env__get_cpu_topology() which validates both NULL and bounds. Also bounds-check al->cpu before the cast to struct perf_cpu (int16_t): without this, values like 65536 silently truncate to 0, bypassing the accessor's internal check and returning CPU 0's topology.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐧Linux	`Kernel`	≥ 4.4.0&&< 6.18.40	6.18.40

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Kernel. 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.
Fix
Update Kernel to 6.18.40 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-80670 is resolved across your whole dependency graph.
Workarounds
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-2026-80670 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-2026-80670. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

In the Linux kernel, the following vulnerability has been resolved: perf tools: Use perf_env__get_cpu_topology() in machine__resolve() machine__resolve() accesses env->cpu[al->cpu].socket_id after checking al->cpu >= 0 and env->cpu != NULL, but without validating al->cpu against env->nr_cpus_avail. Since al->cpu comes from the untrusted perf.data sample, a crafted file with a large CPU index causes an out-of-bounds heap read. Use perf_env__get_cpu_topology() which validates both NULL and bounds. Also bounds-check al->cpu before the cast to struct perf_cpu (int16_t): without this, values li

O3 Security · Impact-Aware SCA

Is CVE-2026-80670 in your dependencies?

O3 detects CVE-2026-80670 across Linux dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

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