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CVE-2026-80671

Critical Vulnerability: CVE-2026-80671

In the Linux kernel, the following vulnerability has been resolved: perf sched: Fix register_pid() overflow, strcpy, and BUG_ON register_pid() has several issues when processing untrusted perf.data: 1. Integer overflow: (pid + 1) * sizeof(struct task_desc *) can wrap to a small value on 32-bit systems when pid is large (e.g. 0x40000000), causing realloc to return a tiny buffer followed by out-of-bounds writes in the initialization loop. 2. Heap buffer overflow: strcpy(task->comm, co

Saturday, August 29, 2026Vulnios Threat Intelligence
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Vulnerability Snapshot

CVE-2026-80671 is rated CRITICAL — exploitation is trivial or already observed in the wild and impact is severe. Patch immediately, not on the next maintenance window.

Executive Summary

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

perf sched: Fix register_pid() overflow, strcpy, and BUG_ON

register_pid() has several issues when processing untrusted perf.data:

  • Integer overflow: (pid + 1) sizeof(struct task_desc ) can wrap

    • to a small value on 32-bit systems when pid is large (e.g.

    0x40000000), causing realloc to return a tiny buffer followed by

    out-of-bounds writes in the initialization loop.

  • Heap buffer overflow: strcpy(task->comm, comm) copies the

    • untrusted comm string into a fixed 20-byte COMM_LEN buffer with

    no length check.

  • BUG_ON on allocation failure: perf.data is untrusted input, so

    • allocation failures should be handled gracefully rather than

    killing the process.

  • Realloc of sched->tasks assigned directly back, leaking the old

    • pointer on failure; nr_tasks incremented before the realloc,

    leaving corrupted state on failure.

    Cap pid at PID_MAX_LIMIT (4194304, matching the kernel's maximum

    on 64-

    Why It Matters

    CVE-2026-80671 is rated CRITICAL severity, requiring immediate attention from security teams.

    CVSS Base Score: 9.3/10

    EPSS (Exploit Prediction): 0.2% probability of exploitation in the next 30 days.

    🛡️What Defenders Should Check

  • Check if you are affected — Review your asset inventory for products listed in CVE-2026-80671.
  • Apply available patches — Visit vendor advisories for the latest security updates.
  • Monitor for exploitation — Check your SIEM/IDS logs for related indicators.

    • Use Vulnios to continuously monitor your exposure to CVE-2026-80671 and similar vulnerabilities.

    References & Sources

  • https://git.kernel.org/stable/c/5949d339f5ec98752d56dcd4e36f619a59d513a5
  • https://git.kernel.org/stable/c/5ea1dcc9418c4e06ce29ed5170596f497ba86872
  • https://git.kernel.org/stable/c/652cea73b7b7b7c622a2be670e44e3c499c6d49f

    • How Vulnios Detects This

    Vulnios scans for this vulnerability using Trivy and Grype for SBOM-based CVE matching and Vulnios CVE feed continuous monitoring against your asset inventory. Run a scan against your environment to see whether you are exposed; findings are linked back to the original CVE record so triage starts with the patch path already known.

    AI Security Advisor

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    Sources

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    Frequently Asked Questions

    What is CVE-2026-80671?

    CVE-2026-80671 is a critical-severity vulnerability tracked under the Common Vulnerabilities and Exposures program. In the Linux kernel, the following vulnerability has been resolved:

    perf sched: Fix register_pid() overflow, strcpy, and BUG_ON

    register_pid() has several issues when processing untrusted perf.data:

    Am I affected?

    Affected technology is listed in the Affected Products section above. If your asset inventory contains any of them, assume in-scope until you can prove otherwise.

    How urgent is the response?

    Critical: do not wait for your normal patch cycle. Verify exposure today, apply the vendor patch immediately, and add detection rules for any post-exploit indicators.

    How do I remediate?

    Apply the vendor patch listed in the upstream advisory linked under Sources. If the patch is not yet available, follow the vendor-supplied workaround (often a config flag or feature disable) and add detections for the published exploit pattern in your SIEM. Re-scan after the patch lands to confirm the finding clears.

    Where can I track exploitation activity?

    Watch CISA's Known Exploited Vulnerabilities catalog for CVE-2026-80671. Cross-reference with public exploit databases and your own SIEM/IDS for indicator-of-compromise patterns. Vulnios tracks KEV status automatically and surfaces it on the asset findings view.

    How does Vulnios help with this?

    Vulnios continuously cross-references your asset inventory against the live CVE feed (NVD, vendor advisories, CISA KEV, and curated OSINT). When a new CVE matches your environment, you get a prioritized finding with the severity, KEV status, exploit-prediction (EPSS), and a direct path to the vendor patch. You can start a free scan from the homepage.

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