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CVE-2026-74587

Critical Vulnerability: CVE-2026-74587

In the Linux kernel, the following vulnerability has been resolved: sctp: fix use-after-free of cached ASCONF chunk addip_last_asconf caches the outstanding outbound ASCONF chunk. The normal ASCONF-ACK completion path releases the chunk and clears the pointer. However, sctp_asconf_queue_teardown() releases the cached chunk without clearing addip_last_asconf. During peer restart handling, sctp_sf_do_dupcook_a() queues SCTP_CMD_PURGE_ASCONF_QUEUE, which invokes sctp_asconf_queue_teardown() whil

Tuesday, August 25, 2026Vulnios Threat Intelligence
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Vulnerability Snapshot

CVE-2026-74587 is rated CRITICAL โ€” 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:

sctp: fix use-after-free of cached ASCONF chunk

addip_last_asconf caches the outstanding outbound ASCONF chunk. The normal

ASCONF-ACK completion path releases the chunk and clears the pointer.

However, sctp_asconf_queue_teardown() releases the cached chunk without

clearing addip_last_asconf. During peer restart handling,

sctp_sf_do_dupcook_a() queues SCTP_CMD_PURGE_ASCONF_QUEUE, which invokes

sctp_asconf_queue_teardown() while the association remains alive and leaves

the pointer dangling.

A delayed authenticated ASCONF-ACK can then reach sctp_sf_do_asconf_ack(),

which accesses the stale chunk and passes it to sctp_process_asconf_ack(),

causing a use-after-free and a second release.

Clearing the pointer exposes a race with T4 expiry. Peer restart handling

queues the timer stop before the purge, but SCTP_CMD_TIMER_STOP uses

timer_delete(), which does not wait for a callback already running on

another CPU. Such a cal

Why It Matters

CVE-2026-74587 is rated CRITICAL severity, requiring immediate attention from security teams.

CVSS Base Score: 9.8/10

๐Ÿ›ก๏ธWhat Defenders Should Check

  • Check if you are affected โ€” Review your asset inventory for products listed in CVE-2026-74587.
  • Apply available patches โ€” Visit vendor advisories for the latest security updates.
  • Monitor for exploitation โ€” Check your SIEM/IDS logs for related indicators.
  • Use Vulnios to continuously monitor your exposure to CVE-2026-74587 and similar vulnerabilities.

    References & Sources

    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.

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    Sources

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    Frequently Asked Questions

    What is CVE-2026-74587?

    CVE-2026-74587 is a critical-severity vulnerability tracked under the Common Vulnerabilities and Exposures program. In the Linux kernel, the following vulnerability has been resolved:

    sctp: fix use-after-free of cached ASCONF chunk

    addip_last_asconf caches the outstanding outbound ASCONF chunk. The normal

    ASCONF-

    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-2026-74587. 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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