7.5

CVE-2026-53394: nfsd: avoid leaking pre-allocated openowner on unconfirmed retry race

Modified
AliasesUBUNTU-CVE-2026-53394DEBIAN-CVE-2026-53394
Published 19-07-2026Last modified 19-10-2026

Vulnerability summary

CVE-2026-53394 is a high (CVSS 7.5) vulnerability in linux. EPSS estimates a 0.63% chance of exploitation in the next 30 days, higher than 50.2% of scored vulnerabilities.

Priority
Prioritisesevere

Severe, CVSS 7.5 (CVE.org); no exploitation reported by the 5 checked sources; EPSS 1% (FIRST, 03-11-2026)

Source freshness unavailable

How is this decided?
CVSS score
7.5/10
010
High · v3.1 (CVE.org)
EPSS score
0.63%
0%100%
Low · +0.17 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 19 · Related 18
MGASA-2026-0312OPENSUSE-SU-2026:11339-1OPENSUSE-SU-2026:21555-1SUSE-SU-2026:23066-1SUSE-SU-2026:23068-1SUSE-SU-2026:23221-1

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: nfsd: avoid leaking pre-allocated openowner on unconfirmed retry race When find_or_alloc_open_stateowner() encounters an unconfirmed owner, it calls release_openowner() and sets oo = NULL. Control then falls through past the `if (oo)` guard -- which would have freed any pre-allocated `new` -- and unconditionally executes `new = alloc_stateowner(...)`. If `new` was already allocated on a prior iteration, the pointer is silently overwritten and the previous allocation (slab object + owner name buffer) is leaked. This requires a race: two NFSv4.0 OPEN threads with the same owner string, where a concurrent thread inserts a new unconfirmed owner into the hash between retry iterations. The window is narrow but repeatable under adversarial conditions. Fix by adding `goto retry` after `oo = NULL` so the already-allocated `new` is reused on the next iteration rather than overwritten.

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.63%

Chance of exploitation in the next 30 days

Percentile

50%

Versus all other CVEs

30-day change

Increase +0.17 pp

From 0.46% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.

Ubuntu119 products
  • linux< 7.0.0-31.31
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-aws< 7.0.0-1012.12
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Linux2 products
  • linux≥ 23df17788c6212809848f836b10c4f85b16843a5, < c9aefb2b5f11337c9202c5bd0c45d71198449718 | ≥ 23df17788c6212809848f836b10c4f85b16843a5, < 017a6150106b054cc84d1b0582d97bd3a74d4281 | ≥ 23df17788c6212809848f836b10c4f85b16843a5, < a10bf67fe06469a71a401f72f328237345d553c0 | ≥ 23df17788c6212809848f836b10c4f85b16843a5, < 57aee7a35bb12753057c5b65d72d1f46c0e95b07 | 6.10
  • linux_kernel≥ 6.10, < 6.12.95 | ≥ 6.13, < 6.18.38 | ≥ 6.19, < 7.1.3
Debian1 product
  • linux< 6.12.95-1 | < 7.1.3-1

3 vendors · 122 products

References

19 links
Show all 19 references