CVE-2026-63800

CRITICALPre-NVD 9.89.8
EchelonGraph scoreHIGH confidence

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2026-07-19. a secondary CVSS source baseline 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 4 sources updated this week
9.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 9.8Exploit: 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:

pNFS: Fix use-after-free in pnfs_update_layout()

When hitting the NFS_LAYOUT_RETURN branch in pnfs_update_layout(), the code calls pnfs_prepare_to_retry_layoutget(lo). If it succeeds, pnfs_put_layout_hdr(lo) is called before trace_pnfs_update_layout(), which still references 'lo'. This results in a use-after-free when the tracepoint accesses lo's fields.

Fix this by moving the tracepoint call before pnfs_put_layout_hdr(lo).

CVSS v3
9.8
EG Score
9.8(high)
EG Risk
49(Track)
EG Risk 49/100SSVC: 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
Severity98% × 45%
Exploitation1% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
1%
EPSS %ILE
40%
KEV
Not listed

Published

July 19, 2026

Last Modified

July 20, 2026

Advisory Details (8)

Auto-updated Jul 25, 2026
No patch confirmed yet.
generic

pNFS: Fix use-after-free in pnfs_update_layout() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/9c0fb5c09ae5bd68dc0038692af8127029cb0385
generic

pNFS: Fix use-after-free in pnfs_update_layout() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/9645aaf689aff57427ece3b9fa47d5b5399417f4
generic

pNFS: Fix use-after-free in pnfs_update_layout() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/7e37e9b3e82ade881e1798e2f4fcc54aff7793c1
generic

pNFS: Fix use-after-free in pnfs_update_layout() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/4ad8b9a85dbf57ca532ee9e65ad7e6498bfbbf98
generic

pNFS: Fix use-after-free in pnfs_update_layout() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/2883ddd7542b4437a2ab4908fe2773f690e20889
generic

pNFS: Fix use-after-free in pnfs_update_layout() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/200e7637f4d6a1342987045eea72641524f909dc
generic

pNFS: Fix use-after-free in pnfs_update_layout() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/1f24b8302c77dcaf79c64c073877a3b9f4dd25d2
generic

pNFS: Fix use-after-free in pnfs_update_layout() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/13e198a90ca4050f4bee8a3f23680389a6563ccc

Vendor Advisories for CVE-2026-63800(2)

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 28× in last 7d / 31× 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. 2026-07-27 11:39 UTCGHSA enrichment
  2. 2026-07-27 07:36 UTCGHSA enrichment
  3. 2026-07-27 03:34 UTCGHSA enrichment
  4. 2026-07-26 23:17 UTCGHSA enrichment
  5. 2026-07-26 19:15 UTCGHSA enrichment
  6. 2026-07-26 15:12 UTCEG score recompute
  7. 2026-07-26 15:12 UTCGHSA enrichment
  8. 2026-07-26 14:54 UTCEPSS rescore
  9. 2026-07-26 14:54 UTCEPSS rescore
  10. 2026-07-26 11:10 UTCEG score recompute
  11. 2026-07-26 11:10 UTCGHSA enrichment
  12. 2026-07-25 14:18 UTCEPSS rescore
  13. 2026-07-25 14:18 UTCEPSS rescore
  14. 2026-07-24 14:18 UTCEPSS rescore
  15. 2026-07-24 14:18 UTCEPSS rescore
  16. 2026-07-23 14:18 UTCEPSS rescore
  17. 2026-07-23 14:18 UTCEPSS rescore
  18. 2026-07-23 03:22 UTCEG score recompute
  19. 2026-07-22 14:08 UTCEPSS rescore
  20. 2026-07-22 14:08 UTCEPSS rescore
  21. 2026-07-21 15:25 UTCEPSS rescore
  22. 2026-07-21 15:25 UTCEPSS rescore
  23. 2026-07-20 17:46 UTCEG score recompute
  24. 2026-07-20 17:46 UTCGHSA enrichment
  25. 2026-07-20 17:08 UTCEPSS rescore
Show 6 more
  1. 2026-07-20 14:46 UTCEG score recompute 9.80
  2. 2026-07-20 14:45 UTCGHSA enrichment
  3. 2026-07-20 14:32 UTCMITRE cvelistV5CVSS v3 → 9.8 · severity → CRITICAL
  4. 2026-07-19 12:26 UTCNVD update
  5. 2026-07-19 12:14 UTCEG score recompute
  6. 2026-07-19 12:10 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-63800?
CVE-2026-63800 is a critical vulnerability published on July 19, 2026. In the Linux kernel, the following vulnerability has been resolved: pNFS: Fix use-after-free in pnfsupdatelayout() When hitting the NFSLAYOUTRETURN branch in pnfsupdatelayout(), the code calls pnfspreparetoretrylayoutget(lo). If it succeeds, pnfsputlayouthdr(lo) is called before…
When was CVE-2026-63800 disclosed?
CVE-2026-63800 was first published in the National Vulnerability Database on July 19, 2026, with the most recent update on July 20, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-63800 actively exploited?
CVE-2026-63800 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1% probability of exploitation in the next 30 days, which ranks it in the top 60.1% of all scored CVEs.
What is the CVSS score of CVE-2026-63800?
CVE-2026-63800 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2026-63800?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-63800, 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.

Dependency Blast Radius

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