CVE-2026-97566

UNRATEDCVSS · not yet scoredTrending — 6 sources updated this week
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EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • No CVSS published and no exploitation signals yet
CISA-KEV: Not listedEPSS PROB: 0.2%CVSS v2: —Exploit: None knownExposed services: Not assessed

No fix is confirmed yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for the fix.

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

mptcp: pm: kernel: drop pending ADD_ADDR when removing ID0

The in-kernel MPTCP path manager can leave a stale ADD_ADDR announcement entry alive when removing the id 0 endpoint. This happens because the id 0 removal path does not tear down pending announcements, unlike the non-zero id path.

When the PM later reselects id 0 after adding another signal endpoint, it finds the stale anno_list entry and hits WARN_ON_ONCE(mptcp_pm_is_kernel()) in mptcp_pm_announced_alloc().

Root cause: asymmetry between removal paths.

  • Non-zero id path: mptcp_nl_remove_subflow_and_signal_addr() calls
mptcp_pm_remove_announced() to clean up.
  • Id 0 path: mptcp_nl_remove_id_zero_address() skips cleanup entirely.

Fix by making the id 0 path symmetric: call mptcp_pm_announced_remove() and decrement add_addr_signaled before queuing the RM_ADDR.

Subtle detail: signal endpoints are stored in anno_list with port 0, but msk_local carries the connection's local port. In other words, entries linked to ID0 paths should have port == 0. A follow-up patch will ensure that. mptcp_pm_announced_remove() uses use_port=true for comparison. So clear the port before the lookup.

CVSS v3
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EchelonGraph score
Not yet assessedNo source has published severity data for this CVE yet — no CVSS score from NVD or a CNA, no GitHub advisory, and it is not in CISA KEV. This is not a rating of zero; we cannot assess it yet.
EG Score
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EG Risk
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EPSS PROB
0.2%
EPSS %ILE
8th
KEV
Not listed

Published

September 25, 2026

Last Modified

October 3, 2026

References (4)

Vendor Advisories for CVE-2026-97566(2)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(3 across 3 ecosystems)
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.1.106-1 ... 7.2~rc7-1~exp1 (360 versions)
  • every version on: no fix on record
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Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.12.100-1 ... 7.2~rc7-1~exp1 (183 versions)
  • every version on: no fix on record
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Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.12.100-1 ... 7.2~rc7-1~exp1 (180 versions)
  • every version up to 7.2.7-1: fixed in 7.2.7-1
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Data Freshness Timeline

(refreshed 14× in last 7d / 22× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-10-04 23:23 UTCEPSS rescore
  2. 2026-10-03 14:26 UTCEPSS rescore
  3. 2026-10-03 11:29 UTCVendor advisory
  4. 2026-10-03 11:29 UTCGHSA enrichment
  5. 2026-10-03 11:26 UTCNVD update
  6. 2026-10-03 11:10 UTCMITRE cvelistV5
  7. 2026-10-02 17:57 UTCEPSS rescore
  8. 2026-10-01 19:51 UTCEPSS rescore
  9. 2026-10-01 07:00 UTCEG score recompute
  10. 2026-10-01 07:00 UTCVendor advisory
  11. 2026-10-01 07:00 UTCGHSA enrichment
  12. 2026-09-30 15:04 UTCEPSS rescore
  13. 2026-09-28 13:52 UTCEPSS rescore
  14. 2026-09-28 13:52 UTCEPSS rescore
  15. 2026-09-28 09:19 UTCEG score recompute
  16. 2026-09-28 09:19 UTCVendor advisory
  17. 2026-09-28 09:19 UTCGHSA enrichment
  18. 2026-09-27 13:49 UTCEPSS rescore
  19. 2026-09-26 15:59 UTCEPSS rescore
  20. 2026-09-25 11:29 UTCNVD update
  21. 2026-09-25 10:40 UTCEG score recompute
  22. 2026-09-25 10:27 UTCMITRE cvelistV5first tracked

Frequently asked(4)

What is CVE-2026-97566?
CVE-2026-97566 is a publicly disclosed vulnerability published on September 25, 2026. In the Linux kernel, the following vulnerability has been resolved: mptcp: pm: kernel: drop pending ADD_ADDR when removing ID0 The in-kernel MPTCP path manager can leave a stale ADD_ADDR announcement entry alive when removing the id 0 endpoint. This happens because the id 0 removal path does not…
When was CVE-2026-97566 disclosed?
CVE-2026-97566 was first published on September 25, 2026, with the most recent update on October 3, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-97566 actively exploited?
CVE-2026-97566 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.2% probability of exploitation in the next 30 days (8th percentile of EPSS-scored CVEs).
How do I remediate CVE-2026-97566?
No fix for CVE-2026-97566 is confirmed yet. Until one is published, restrict network exposure of the affected system or apply the vendor's mitigation — for example, keep it off the internet or limit it to trusted networks — and watch the vendor's advisory for the fix. The vendor advisories EchelonGraph has for CVE-2026-97566 are linked in the Vendor Advisories panel on this page.

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