CVE-2026-90234

HIGHPre-NVD 7.57.5—
EchelonGraph scoreHIGH confidence

Score 7.5 from GitHub Security Advisory (severity: HIGH) published 2026-09-17. A secondary CVSS source baseline 7.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 3 sources updated this week
7.5EG
EchelonGraph verdictPlan mitigationSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.5%CVSS: 7.5Exploit: 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:

NFS: Return a delegation the client fails to record

When an NFS server grants a delegation in an OPEN reply, nfs_inode_set_delegation() records it on the client. However, three of its error flows return without sending DELEGRETURN.

A delegation can be relinquished only by DELEGRETURN (RFC 8881 Section 20.2.4), so dropping one silently leaves the server believing the client still holds it. If the server happens to recall that delegation, the client answers CB_RECALL with NFS4ERR_BADHANDLE because it has no record of the stateid. The server revokes the delegation and moves it onto its cl_revoked list, because the client never sends the FREE_STATEID that would drain it. Every subsequent SEQUENCE reply then carries SEQ4_STATUS_RECALLABLE_STATE_REVOKED, and the client's state manager loops issuing TEST_STATEID across its delegations without ever clearing the condition.

The window is easy to reach now that a server offers a write delegation on any write OPEN: a delegation recalled for one opener races a re-open that the server answers with a fresh write delegation.

Instead of dropping it, hand the delegation back during these error flows.

CVSS v3
7.5
EG Score
7.5HIGHhigh confidence
EG Risk
38
EG Risk 38/100CISA SSVC

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
Severity75% × 45%
Exploitation0% × 40%
Automatability30% × 15%
CISA SSVC: Track at low or medium mission impact; Track or Attend at high (mission-essential systems).
Action: No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines at low or medium mission impact and sooner than that at high, and watch the vendor's advisory for the fix.
EPSS PROB
0.5%
EPSS %ILE
39th
KEV
Not listed

CISA SSVCTrack at low or medium mission impact; Track or Attend at high (mission-essential systems).

No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines at low or medium mission impact and sooner than that at high, and watch the vendor's advisory for the fix.

Exploitation none (no KEV listing, exploit record or EPSS ≥ 50%) · Automatable unknown (not published for this CVE) · Technical impact partial (CVSS below 9.0). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

September 17, 2026

Last Modified

September 18, 2026

Advisory Details (2)

Auto-updated Sep 18, 2026
No patch confirmed yet.
generic

NFS: Return a delegation the client fails to record - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/92533e49fe3c455088657b862cf3562260c0ce25
generic

NFS: Return a delegation the client fails to record - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/220af23d863995091f0edeb1e6aa0945b3db8b37

Vendor Advisories for CVE-2026-90234(1)

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 (358 versions)
  • every version on: no fix on record
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.12.100-1 ... 7.2~rc7-1~exp1 (181 versions)
  • every version on: no fix on record
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.12.100-1 ... 7.2~rc7-1~exp1 (178 versions)
  • every version up to 7.2.6-1: fixed in 7.2.6-1
—

Data Freshness Timeline

(refreshed 25× in last 7d / 69× 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. 2026-10-05 09:34 UTCEG score recompute
  2. 2026-10-05 09:34 UTCGHSA enrichment
  3. 2026-10-04 23:22 UTCEPSS rescore
  4. 2026-10-04 20:45 UTCGHSA enrichment
  5. 2026-10-04 07:56 UTCGHSA enrichment
  6. 2026-10-03 19:06 UTCEG score recompute
  7. 2026-10-03 19:06 UTCGHSA enrichment
  8. 2026-10-03 06:17 UTCEG score recompute
  9. 2026-10-03 06:17 UTCGHSA enrichment
  10. 2026-10-02 17:27 UTCGHSA enrichment
  11. 2026-10-02 04:35 UTCEG score recompute
  12. 2026-10-02 04:35 UTCGHSA enrichment
  13. 2026-10-01 19:51 UTCEPSS rescore
  14. 2026-10-01 15:14 UTCGHSA enrichment
  15. 2026-10-01 02:25 UTCEG score recompute
  16. 2026-10-01 02:25 UTCGHSA enrichment
  17. 2026-09-30 15:04 UTCEPSS rescore
  18. 2026-09-30 13:36 UTCGHSA enrichment
  19. 2026-09-30 00:44 UTCEG score recompute
  20. 2026-09-30 00:44 UTCGHSA enrichment
  21. 2026-09-29 11:04 UTCGHSA enrichment
  22. 2026-09-28 22:14 UTCEG score recompute
  23. 2026-09-28 22:14 UTCGHSA enrichment
  24. 2026-09-28 13:52 UTCEPSS rescore
  25. 2026-09-28 13:52 UTCEPSS rescore
Show 44 more
  1. 2026-09-28 09:25 UTCGHSA enrichment
  2. 2026-09-27 20:36 UTCEG score recompute
  3. 2026-09-27 20:36 UTCGHSA enrichment
  4. 2026-09-27 13:49 UTCEPSS rescore
  5. 2026-09-27 07:47 UTCGHSA enrichment
  6. 2026-09-26 18:57 UTCEG score recompute
  7. 2026-09-26 18:57 UTCGHSA enrichment
  8. 2026-09-26 15:59 UTCEPSS rescore
  9. 2026-09-26 06:05 UTCEG score recompute
  10. 2026-09-26 06:05 UTCGHSA enrichment
  11. 2026-09-25 17:16 UTCGHSA enrichment
  12. 2026-09-25 04:26 UTCGHSA enrichment
  13. 2026-09-24 15:36 UTCEG score recompute
  14. 2026-09-24 15:36 UTCGHSA enrichment
  15. 2026-09-24 14:04 UTCEPSS rescore
  16. 2026-09-24 02:46 UTCEG score recompute
  17. 2026-09-24 02:46 UTCGHSA enrichment
  18. 2026-09-23 17:54 UTCEPSS rescore
  19. 2026-09-23 13:56 UTCGHSA enrichment
  20. 2026-09-23 01:07 UTCEG score recompute
  21. 2026-09-23 01:07 UTCGHSA enrichment
  22. 2026-09-22 16:01 UTCEPSS rescore
  23. 2026-09-22 12:17 UTCGHSA enrichment
  24. 2026-09-21 23:28 UTCEG score recompute
  25. 2026-09-21 23:28 UTCGHSA enrichment
  26. 2026-09-21 21:09 UTCEPSS rescore
  27. 2026-09-21 10:38 UTCGHSA enrichment
  28. 2026-09-20 21:49 UTCEG score recompute
  29. 2026-09-20 21:49 UTCGHSA enrichment
  30. 2026-09-20 20:16 UTCEPSS rescore
  31. 2026-09-20 08:59 UTCGHSA enrichment
  32. 2026-09-19 20:09 UTCEG score recompute
  33. 2026-09-19 20:09 UTCGHSA enrichment
  34. 2026-09-19 07:19 UTCEG score recompute
  35. 2026-09-19 07:19 UTCGHSA enrichment
  36. 2026-09-18 19:28 UTCEPSS rescore
  37. 2026-09-18 18:30 UTCEG score recompute
  38. 2026-09-18 18:30 UTCGHSA enrichment
  39. 2026-09-18 18:04 UTCEG score recompute▲ 7.50
  40. 2026-09-18 18:03 UTCGHSA enrichment
  41. 2026-09-18 17:59 UTCMITRE cvelistV5CVSS v3 → 7.5 · severity → HIGH
  42. 2026-09-17 17:23 UTCNVD update
  43. 2026-09-17 16:38 UTCEG score recompute
  44. 2026-09-17 16:19 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-90234?
CVE-2026-90234 is a high vulnerability published on September 17, 2026. In the Linux kernel, the following vulnerability has been resolved: NFS: Return a delegation the client fails to record When an NFS server grants a delegation in an OPEN reply, nfsinodeset_delegation() records it on the client. However, three of its error flows return without sending DELEGRETURN. A…
When was CVE-2026-90234 disclosed?
CVE-2026-90234 was first published on September 17, 2026, with the most recent update on September 18, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-90234 actively exploited?
CVE-2026-90234 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.5% probability of exploitation in the next 30 days (39th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-90234?
CVE-2026-90234 has a CVSS base score of 7.5 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-90234?
No fix for CVE-2026-90234 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-2026-90234 are linked in the Vendor Advisories panel on this page.

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