7.5

CVE-2026-89685: nfsd: fix clock domain mismatch in clients_still_reclaiming()

Received
AliasesUBUNTU-CVE-2026-89685DEBIAN-CVE-2026-89685
Published 11-09-2026Last modified 30-10-2026

Vulnerability summary

CVE-2026-89685 is a high (CVSS 7.5) vulnerability in linux. EPSS estimates a 0.61% chance of exploitation in the next 30 days, higher than 49.3% 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
0.61%
0%100%
Low · -0.02 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 10 · Related 10
OPENSUSE-SU-2026:11805-1OPENSUSE-SU-2026:22091-1SUSE-SU-2026:24179-1SUSE-SU-2026:24184-1SUSE-SU-2026:24197-1SUSE-SU-2026:24235-1

Timeline

  1. 11-09-2026
    PublishedVulnerability first disclosed.
  2. 30-10-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: nfsd: fix clock domain mismatch in clients_still_reclaiming() clients_still_reclaiming() computes a deadline from nn->boot_time (CLOCK_REALTIME, ~1.7 billion) but compares it against ktime_get_boottime_seconds() (CLOCK_BOOTTIME, seconds since boot). The comparison is always false — it would take ~54 years of uptime for BOOTTIME to exceed the REALTIME-derived deadline. This means any client can hold the server in grace indefinitely by sending CLAIM_PREVIOUS OPEN requests, blocking all non-reclaim operations for all other clients. Add boot_time_bt (CLOCK_BOOTTIME) alongside the existing boot_time and use it for the deadline computation. boot_time (CLOCK_REALTIME) is preserved for its cl_boot clientid-nonce role.

CVSS metrics

5 scores · 4 sources · 2 versions

EPSS trend

Probability

0.61%

Chance of exploitation in the next 30 days

Percentile

49%

Versus all other CVEs

30-day change

Decrease -0.02 pp

From 0.63% 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.

Ubuntu157 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)
Debian2 products
  • linuxAll versions (No fix recorded) | < 6.12.111-1 | < 7.2.6-1
  • linux-6.12< 6.12.111-1~deb12u1
Linux1 product
  • linux≥ 20b7d86f29d39e8ae19bb29c24ffee70dc385ddf, < 7ca44a63d9a554ba7ad05b06d88746eab08b760e | ≥ 20b7d86f29d39e8ae19bb29c24ffee70dc385ddf, < 2c9efc6b692a153643d0f204b3c3632cb6b5761e | ≥ 20b7d86f29d39e8ae19bb29c24ffee70dc385ddf, < a22ee3a2cadef44f2edeb909ae36bd72450a3a35 | ≥ 20b7d86f29d39e8ae19bb29c24ffee70dc385ddf, < 04c3e4456fe76e8d7c94171009df3165c3262c51 | ≥ 20b7d86f29d39e8ae19bb29c24ffee70dc385ddf, < e92e80c5b043108029bc729b30d12c37158fb9cb | ≥ 20b7d86f29d39e8ae19bb29c24ffee70dc385ddf, < f9cec313efb2fd18d962aad738a4892bce806016 | ≥ 20b7d86f29d39e8ae19bb29c24ffee70dc385ddf, < 9843649196221152b6e5d138a3ce859bdaae1d96 | ≥ 20b7d86f29d39e8ae19bb29c24ffee70dc385ddf, < 09ea3eb9a518565f5bca386e81b993ed8825f5e8 | 5.6

3 vendors · 160 products

References

12 links
Show all 12 references