CVE-2026-80554

CRITICALPre-NVD 9.39.3—
EchelonGraph scoreHIGH confidence

Score 9.3 from GitHub Security Advisory (severity: CRITICAL) published 2026-08-27. a secondary CVSS source baseline 9.3; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 5 sources updated this week
9.3EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 9.3Exploit: None knownExposed: 0

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

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

s390/vfio_ccw: Limit the number of channel program segments

The processing of channel programs, and the CCWs within them, is done recursively. As such, there is an arbitrary (but not architectural) limit to the number of CCWs that can exist in a single channel program.

The vfio-ccw logic breaks these channel programs into segments whenever it encounters a Transfer-In-Channel (TIC) CCW, and the combined number of segments count towards the global limit. Impose an equivalent limit to the number of segments until such logic can be made non-recursive.

CVSS v3
9.3
EG Score
9.3(high)
EG Risk
46(Track)
EG Risk 46/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity93% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
4%
KEV
Not listed

Published

August 26, 2026

Last Modified

August 27, 2026

Advisory Details (5)

Auto-updated Aug 27, 2026
No patch confirmed yet.
generic

s390/vfio_ccw: Limit the number of channel program segments - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/a1625f66eaa1200068a0e2c05bc90e65182fc4e3
generic

s390/vfio_ccw: Limit the number of channel program segments - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/5405c90d6a47b3014e74ee0618a162449abbbc93
generic

s390/vfio_ccw: Limit the number of channel program segments - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/4ee94790490ae8dcc97df8597f07836c8a81bbcf
generic

s390/vfio_ccw: Limit the number of channel program segments - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/15fb4559a7fdf0b8725e433a71cfd03a1313a48b
generic

s390/vfio_ccw: Limit the number of channel program segments - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/06f4d6e5a8af6c2072e8cd39dbc512c683ca7fb2

Vendor Advisories for CVE-2026-80554(1)

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

Data Freshness Timeline

(refreshed 29× in last 7d / 29× 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. 2026-08-30 02:55 UTCEG score recompute
  2. 2026-08-30 02:55 UTCGHSA enrichment
  3. 2026-08-30 01:22 UTCEPSS rescore
  4. 2026-08-29 23:05 UTCGHSA enrichment
  5. 2026-08-29 19:13 UTCGHSA enrichment
  6. 2026-08-29 15:21 UTCGHSA enrichment
  7. 2026-08-29 11:31 UTCGHSA enrichment
  8. 2026-08-29 07:38 UTCGHSA enrichment
  9. 2026-08-29 03:47 UTCGHSA enrichment
  10. 2026-08-28 23:58 UTCEG score recompute
  11. 2026-08-28 23:57 UTCGHSA enrichment
  12. 2026-08-28 21:42 UTCEPSS rescore
  13. 2026-08-28 17:20 UTCGHSA enrichment
  14. 2026-08-28 13:19 UTCGHSA enrichment
  15. 2026-08-28 09:25 UTCGHSA enrichment
  16. 2026-08-28 05:33 UTCGHSA enrichment
  17. 2026-08-28 01:43 UTCGHSA enrichment
  18. 2026-08-27 21:53 UTCGHSA enrichment
  19. 2026-08-27 18:04 UTCEG score recompute
  20. 2026-08-27 18:04 UTCGHSA enrichment
  21. 2026-08-27 14:25 UTCEPSS rescore
  22. 2026-08-27 13:57 UTCGHSA enrichment
  23. 2026-08-27 10:08 UTCEG score recompute
  24. 2026-08-27 10:08 UTCGHSA enrichment
  25. 2026-08-27 06:19 UTCEG score recompute▲ 9.30
Show 4 more
  1. 2026-08-27 06:11 UTCMITRE cvelistV5CVSS v3 → 9.3 · severity → CRITICAL
  2. 2026-08-26 15:43 UTCNVD update
  3. 2026-08-26 14:42 UTCEG score recompute
  4. 2026-08-26 14:41 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-80554?
CVE-2026-80554 is a critical vulnerability published on August 26, 2026. In the Linux kernel, the following vulnerability has been resolved: s390/vfio_ccw: Limit the number of channel program segments The processing of channel programs, and the CCWs within them, is done recursively. As such, there is an arbitrary (but not architectural) limit to the number of CCWs that…
When was CVE-2026-80554 disclosed?
CVE-2026-80554 was first published in the National Vulnerability Database on August 26, 2026, with the most recent update on August 27, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-80554 actively exploited?
CVE-2026-80554 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 96.0% of all scored CVEs.
What is the CVSS score of CVE-2026-80554?
CVE-2026-80554 has a CVSS v3 base score of 9.3 (NVD).
How do I remediate CVE-2026-80554?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-80554, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

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