5.5

CVE-2026-22989: nfsd: check that server is running in unlock_filesystem

Analyzed
AliasesUBUNTU-CVE-2026-22989DEBIAN-CVE-2026-22989
Published 23-01-2026Last modified 11-05-2026

Vulnerability summary

CVE-2026-22989 is a medium (CVSS 5.5) vulnerability in linux. EPSS estimates a 0.14% chance of exploitation in the next 30 days, higher than 2.9% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 5.5, local access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
5.5/10
010
Medium · v3.1 (NVD)
EPSS score
0.14%
0%100%
Low · 0.00 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 14 · Related 13
DSA-6126-1OPENSUSE-SU-2026:20287-1SUSE-SU-2026:0962-1SUSE-SU-2026:1081-1SUSE-SU-2026:20555-1SUSE-SU-2026:20570-1

Timeline

  1. 23-01-2026
    PublishedVulnerability first disclosed.
  2. 11-05-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: nfsd: check that server is running in unlock_filesystem If we are trying to unlock the filesystem via an administrative interface and nfsd isn't running, it crashes the server. This happens currently because nfsd4_revoke_states() access state structures (eg., conf_id_hashtbl) that has been freed as a part of the server shutdown. [ 59.465072] Call trace: [ 59.465308] nfsd4_revoke_states+0x1b4/0x898 [nfsd] (P) [ 59.465830] write_unlock_fs+0x258/0x440 [nfsd] [ 59.466278] nfsctl_transaction_write+0xb0/0x120 [nfsd] [ 59.466780] vfs_write+0x1f0/0x938 [ 59.467088] ksys_write+0xfc/0x1f8 [ 59.467395] __arm64_sys_write+0x74/0xb8 [ 59.467746] invoke_syscall.constprop.0+0xdc/0x1e8 [ 59.468177] do_el0_svc+0x154/0x1d8 [ 59.468489] el0_svc+0x40/0xe0 [ 59.468767] el0t_64_sync_handler+0xa0/0xe8 [ 59.469138] el0t_64_sync+0x1ac/0x1b0 Ensure this can't happen by taking the nfsd_mutex and checking that the server is still up, and then holding the mutex across the call to nfsd4_revoke_states().

CVSS metrics

3 scores · 3 sources · 1 version

EPSS trend

Probability

0.14%

Chance of exploitation in the next 30 days

Percentile

3%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.13% 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: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.

Ubuntu107 products
  • linuxAll versions (No fix recorded)
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-awsAll versions (No fix recorded)
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Linux2 products
  • linux≥ 1ac3629bf012592cb0320e52a1cceb319a05ad17, < d95499900fe52f3d461ed26b7a30bebea8f12914 | ≥ 1ac3629bf012592cb0320e52a1cceb319a05ad17, < e06c9f6c0f554148d4921c2a15bd054260a054ac | ≥ 1ac3629bf012592cb0320e52a1cceb319a05ad17, < d0424066fcd294977f310964bed6f2a487fa4515 | 6.9
  • linux_kernel≥ 6.9, < 6.12.66 | ≥ 6.13, < 6.18.6 | 6.19:rc1 | 6.19:rc2 | 6.19:rc3 | 6.19:rc4
Debian1 product
  • linux< 6.12.69-1 | < 6.18.8-1

3 vendors · 110 products

References

13 links
Show all 13 references