9.8

CVE-2026-63800: linux Use After Free

CVSS: 9.8v3.1CriticalModified
AliasesUBUNTU-CVE-2026-63800DEBIAN-CVE-2026-63800
Published 19-07-2026Last modified 19-10-2026
Open JSON

Vulnerability summary

CVE-2026-63800 is a critical (CVSS 9.8) Use After Free vulnerability in linux. EPSS estimates a 0.53% chance of exploitation in the next 30 days, higher than 43.4% of scored vulnerabilities.

Overall risk
70/100
0100
High · default modelHow is this calculated?
CVSS score
9.8/10
010
Critical · v3.1 (CVE.org)
EPSS score
0.53%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 29 · Related 24
MGASA-2026-0312OPENSUSE-SU-2026:11339-1RHSA-2026:61887RHSA-2026:63013RHSA-2026:63014RHSA-2026:63129

Timeline

  1. 19-07-2026
    PublishedVulnerability first disclosed.
  2. 19-10-2026
    Last modifiedVulnerability information updated.

Description

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 metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.53%

Chance of exploitation in the next 30 days

Percentile

43%

Versus all other CVEs

30-day change

0.00 pp

From 0.53% on 19-09-2026

19-09-202619-10-2026
EPSS score
0.53%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Ubuntu165 products
  • linuxAll versions (No fix recorded) | < 5.15.0-194.204 | < 6.8.0-147.147 | < 7.0.0-31.31
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-awsAll versions (No fix recorded) | < 5.15.0-1116.123 | < 6.8.0-1067.70 | < 7.0.0-1012.12
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Linux2 products
  • linux≥ 06f58dbc49a23c99e5c0f246879ed16667f7bf8f, < 4ad8b9a85dbf57ca532ee9e65ad7e6498bfbbf98 | ≥ 2c8d5fc37fe2384a9bdb6965443ab9224d46f704, < 1f24b8302c77dcaf79c64c073877a3b9f4dd25d2 | ≥ 2c8d5fc37fe2384a9bdb6965443ab9224d46f704, < 9c0fb5c09ae5bd68dc0038692af8127029cb0385 | ≥ 2c8d5fc37fe2384a9bdb6965443ab9224d46f704, < 7e37e9b3e82ade881e1798e2f4fcc54aff7793c1 | ≥ 2c8d5fc37fe2384a9bdb6965443ab9224d46f704, < 2883ddd7542b4437a2ab4908fe2773f690e20889 | ≥ 2c8d5fc37fe2384a9bdb6965443ab9224d46f704, < 200e7637f4d6a1342987045eea72641524f909dc | ≥ 2c8d5fc37fe2384a9bdb6965443ab9224d46f704, < 9645aaf689aff57427ece3b9fa47d5b5399417f4 | ≥ 2c8d5fc37fe2384a9bdb6965443ab9224d46f704, < 13e198a90ca4050f4bee8a3f23680389a6563ccc | aa2399f55eff4ec78330bb6fe55f9df53e5cae0c | ≥ 5.10.9, < 5.10.260 | ≥ 5.4.91, < 5.5 | 5.11
  • linux_kernelEOL≥ 5.4.91, < 5.5 | ≥ 5.10.9, < 5.10.260 | ≥ 5.11.1, < 5.15.211 | ≥ 5.16, < 6.1.177 | ≥ 6.2, < 6.6.144 | ≥ 6.7, < 6.12.95 | ≥ 6.13, < 6.18.38 | ≥ 6.19, < 7.1.3 | 5.11 | 5.11:rc4 | 5.11:rc5 | 5.11:rc6 | 5.11:rc7
Debian1 product
  • linux< 6.1.177-1 | < 6.12.95-1 | < 7.1.3-1

3 vendors · 168 products

References

36 links
Show all 36 references