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TI-2026-18426 Aliases CVE-2026-22989GHSA-rph5-qwhf-vw4p

nfsd: check that server is running in unlock_filesystem

Priority LOW 24Published · Updated

Key facts

Attack vector
Local
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
None · None · High
Fix status
Partial Red Hat: 3 without a fix

Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat.

Summary

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().

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00135 3rd percentileScored 2026-11-07
Fix Partial Linux (Linux): 6.12.66, 6.18.6, 6.19Red Hat: 3 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
LinuxLinux6.9 and later6.12.66, 6.18.6, 6.19Patch availableCNA
  • Linux VendorLinux Affected 6.9 and later Fixed in 6.12.66, 6.18.6, 6.19 Patch available CNA

CPE configurations NVD · 5

CPEVersionsRoleVendor
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*6.9 to before 6.12.66; 6.13 to before 6.18.6VulnerableLinux
cpe:2.3:o:linux:linux_kernel:6.19:rc1:*:*:*:*:*:*6.19 rc1VulnerableLinux
cpe:2.3:o:linux:linux_kernel:6.19:rc2:*:*:*:*:*:*6.19 rc2VulnerableLinux
cpe:2.3:o:linux:linux_kernel:6.19:rc3:*:*:*:*:*:*6.19 rc3VulnerableLinux
cpe:2.3:o:linux:linux_kernel:6.19:rc4:*:*:*:*:*:*6.19 rc4VulnerableLinux
  • cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 6.9 to before 6.12.66; 6.13 to before 6.18.6 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:6.19:rc1:*:*:*:*:*:* Versions 6.19 rc1 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:6.19:rc2:*:*:*:*:*:* Versions 6.19 rc2 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:6.19:rc3:*:*:*:*:*:* Versions 6.19 rc3 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:6.19:rc4:*:*:*:*:*:* Versions 6.19 rc4 Vulnerable ·Linux

Remediation

  • Fix · CNA Linux (Linux) Fixed in 6.12.66, 6.18.6, 6.19

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux 10AffectedNo fix yet
Red Hat Enterprise Linux 6AffectedNo fix planned: Out of support scope
Red Hat Enterprise Linux 9AffectedNo fix yet
Not affected: 2 products
  • Red Hat Enterprise Linux 7
  • Red Hat Enterprise Linux 8

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-22989
  2. 2026-10-03 Alias added: GHSA-rph5-qwhf-vw4p
  3. 2026-11-05 CISA SSVC decision points changed

References

Patch 3

  • TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
  • TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
  • TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
  • TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
  • TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
  • TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
See all 15278 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences