5.5

CVE-2026-53393: linux

CVSS: 5.5v3.1MediumAnalyzed
AliasesUBUNTU-CVE-2026-53393DEBIAN-CVE-2026-53393
Published 19-07-2026Last modified 17-08-2026
Open JSON

Vulnerability summary

CVE-2026-53393 is a medium (CVSS 5.5) vulnerability in linux. EPSS estimates a 0.13% chance of exploitation in the next 30 days, higher than 2.3% of scored vulnerabilities.

Overall risk
22/100
0100
Low · default modelHow is this calculated?
CVSS score
5.5/10
010
Medium · v3.1 (NVD)
EPSS score
0.13%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 33 · Related 32
MGASA-2026-0312OPENSUSE-SU-2026:11339-1OPENSUSE-SU-2026:21555-1SUSE-SU-2026:23066-1SUSE-SU-2026:23068-1SUSE-SU-2026:23193-1

Timeline

  1. 19-07-2026
    PublishedVulnerability first disclosed.
  2. 17-08-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: nfsd: reset write verifier on deferred writeback errors nfsd_vfs_write() and nfsd_commit() both call filemap_check_wb_err() to detect deferred writeback errors, but neither rotates the server's write verifier (nn->writeverf) when this check fails. Every other durable-storage-failure path in these functions calls commit_reset_write_verifier() before returning an error. The missing rotation means clients holding UNSTABLE write data under the current verifier will COMMIT, receive the unchanged verifier back, and conclude their data is durable — silently dropping data that failed writeback. This violates the UNSTABLE+COMMIT durability contract (RFC 1813 §3.3.7, RFC 8881 §18.32). Add commit_reset_write_verifier() calls at both filemap_check_wb_err() error sites, matching the pattern used by adjacent error paths in the same functions. The helper already filters -EAGAIN and -ESTALE internally, so the calls are unconditionally safe.

CVSS metrics

3 scores · 3 sources · 1 version

EPSS trend

Probability

0.13%

Chance of exploitation in the next 30 days

Percentile

2%

Versus all other CVEs

30-day change

0.00 pp

From 0.13% on 19-09-2026

19-09-202619-10-2026
EPSS score
0.13%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

No weakness data has been published for this record.

Affected systems

Ubuntu157 products
  • linuxAll versions (No fix recorded) | < 5.15.0-198.208 | < 6.8.0-147.147 | < 7.0.0-31.31
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-awsAll versions (No fix recorded) | < 5.15.0-1117.124 | < 6.8.0-1067.70 | < 7.0.0-1012.12
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Linux2 products
  • linux≥ f14816f2f928c560d28ba344af689f56efcd6f55, < b8e5894e56cff70fa245628fe16f0ad6367f8090 | ≥ 3145fe0ebb16e1715ad541a301bc6675c8375fcd, < bc2baca02ec56da7707a74ed5d340b0a1dff1841 | ≥ 555dbf1a9aac6d3150c8b52fa35f768a692f4eeb, < 43b65d2997963e80e8d8d86520bcb1e0751227de | ≥ 555dbf1a9aac6d3150c8b52fa35f768a692f4eeb, < 666e837b247fcadf2d8d508b9b0e49d720393eb4 | ≥ 555dbf1a9aac6d3150c8b52fa35f768a692f4eeb, < 1dd664b39774a9c89b72de8e59bf9ef4b3aaff2e | ≥ 555dbf1a9aac6d3150c8b52fa35f768a692f4eeb, < 4367afc119c51e17a616f6908772b7e2c2c4013f | ≥ 555dbf1a9aac6d3150c8b52fa35f768a692f4eeb, < b027cca33c97354149fcc0ddeede4525c41093cd | ≥ 555dbf1a9aac6d3150c8b52fa35f768a692f4eeb, < 2090b05803faab8a9fa62fbff871007862cac1b7 | ≥ 5.10.124, < 5.10.261 | ≥ 5.15.49, < 5.15.212 | 5.17
  • linux_kernel≥ 5.10.124, < 5.10.261 | ≥ 5.15.49, < 5.15.212 | ≥ 5.17, < 6.1.178 | ≥ 6.2, < 6.6.145 | ≥ 6.7, < 6.12.95 | ≥ 6.13, < 6.18.38 | ≥ 6.19, < 7.1.3
Debian1 product
  • linux< 6.1.180-1 | < 6.12.95-1 | < 7.1.3-1

3 vendors · 160 products

References

32 links
Show all 32 references