8.8

CVE-2026-64138: linux

CVSS: 8.8v3.1HighAnalyzed
AliasesUBUNTU-CVE-2026-64138DEBIAN-CVE-2026-64138
Published 19-07-2026Last modified 05-08-2026
Open JSON

Vulnerability summary

CVE-2026-64138 is a high (CVSS 8.8) vulnerability in linux. EPSS estimates a 0.41% chance of exploitation in the next 30 days, higher than 34.3% of scored vulnerabilities.

Overall risk
35/100
0100
Medium · default modelHow is this calculated?
CVSS score
8.8/10
010
High · v3.1 (CVE.org)
EPSS score
0.41%
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 20 · Related 20
USN-8593-1USN-8603-1USN-8618-1USN-8663-1USN-8664-1USN-8728-1

Timeline

  1. 19-07-2026
    PublishedVulnerability first disclosed.
  2. 05-08-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: ksmbd: validate SID in parent security descriptor during ACL inheritance Introduce smb_validate_ntsd_sid() helper to safely validate Owner SID and Group SID inside the NT Security Descriptor (smb_ntsd) retrieved from the parent directory.

CVSS metrics

5 scores · 4 sources · 2 versions

EPSS trend

Probability

0.41%

Chance of exploitation in the next 30 days

Percentile

34%

Versus all other CVEs

30-day change

0.00 pp

From 0.41% on 19-09-2026

19-09-202619-10-2026
EPSS score
0.41%

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

Ubuntu155 products
  • linuxAll versions (No fix recorded) | < 6.8.0-139.139 | < 7.0.0-28.28
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-awsAll versions (No fix recorded) | < 6.8.0-1064.67 | < 7.0.0-1009.9
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Linux2 products
  • linux≥ e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9, < f0e5c9c663badc9982e6941322eef1cb17de0f11 | ≥ e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9, < 18d8db24b0a5b7be4829238dd4022236df02d421 | ≥ e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9, < 1c9d0646a9959752f11ca1080dc1ff26bd1756cb | ≥ e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9, < 69f030cf95488ae1186c72ac8c66fd279664ea7f | 5.15
  • linux_kernel≥ 5.15, < 6.12.92 | ≥ 6.13, < 6.18.34 | ≥ 6.19, < 7.0.11 | 7.1:rc1 | 7.1:rc2 | 7.1:rc3 | 7.1:rc4
Debian1 product
  • linuxAll versions (No fix recorded) | < 6.12.94-1 | < 7.0.12-1

3 vendors · 158 products

References

28 links
Show all 28 references