7.5

CVE-2026-53026: NFSD: fix nfs4_file access extra count in nfsd4_add_rdaccess_to_wrdeleg

Analyzed
AliasesUBUNTU-CVE-2026-53026DEBIAN-CVE-2026-53026
Published 24-06-2026Last modified 05-08-2026

Vulnerability summary

CVE-2026-53026 is a high (CVSS 7.5) vulnerability in linux. EPSS estimates a 0.43% chance of exploitation in the next 30 days, higher than 36.9% of scored vulnerabilities.

Priority
Prioritisesevere

Severe, CVSS 7.5 (CVE.org); no exploitation reported by the 5 checked sources; EPSS 0% (FIRST, 03-11-2026)

Source freshness unavailable

How is this decided?
CVSS score
7.5/10
010
High · v3.1 (CVE.org)
EPSS score
0.43%
0%100%
Low · -0.18 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 12 · Related 11
RHSA-2026:61887USN-8566-1USN-8568-1USN-8569-1USN-8593-1USN-8603-1

Timeline

  1. 24-06-2026
    PublishedVulnerability first disclosed.
  2. 05-08-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: NFSD: fix nfs4_file access extra count in nfsd4_add_rdaccess_to_wrdeleg In nfsd4_add_rdaccess_to_wrdeleg, if fp->fi_fds[O_RDONLY] is already set by another thread, __nfs4_file_get_access should not be called to increment the nfs4_file access count since that was already done by the thread that added READ access to the file. The extra fi_access count in nfs4_file can prevent the corresponding nfsd_file from being freed. When stopping nfs-server service, these extra access counts trigger a BUG in kmem_cache_destroy() that shows nfsd_file object remaining on __kmem_cache_shutdown. This problem can be reproduced by running the Git project's test suite over NFS.

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.43%

Chance of exploitation in the next 30 days

Percentile

37%

Versus all other CVEs

30-day change

Decrease -0.18 pp

From 0.61% 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

No weakness data has been published for this record.

Affected systems

Version check

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

Ubuntu118 products
  • linuxAll versions (No fix recorded) | < 7.0.0-28.28
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-awsAll versions (No fix recorded) | < 7.0.0-1009.9
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Linux2 products
  • linux≥ c07dc84ed67c5a182273171639bacbbb87c12175, < 4584229395d0d65bd517780afe97ffea07cb2c3d | ≥ 8072e34e1387d03102b788677d491e2bcceef6f5, < b81572b073441dfd32213e41857676d0dbff4665 | ≥ 8072e34e1387d03102b788677d491e2bcceef6f5, < b48f44f36e6607b2f818560f19deb86b4a9c717b | ≥ 6.18.4, < 6.18.33 | 6.19
  • linux_kernelEOL≥ 6.18.4, < 6.18.33 | ≥ 6.19.1, < 7.0.10 | 6.19 | 6.19:rc4 | 6.19:rc5 | 6.19:rc6 | 6.19:rc7 | 6.19:rc8
Debian1 product
  • linux< 7.0.10-1

3 vendors · 121 products

References

18 links
Show all 18 references