Vulnerability in Samba
CVE-2026-2340
A flaw was found in Samba’s vfs_worm module. The module is intended to provide write-once, read-many (WORM) protections by preventing modification of files after a configurable grace period. Due to insufficient validation during rename operations, an authenticated user with write access to a share could overwrite a protected file by renaming a newly created file over the existing WORM-protected file.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N.
EPSS exploit prediction
EPSS: 0.009 (59.4th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 59th percentile — 59.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.009 · newest: 0.009 · change: 0.000
Affected products
- Samba
- Red Hat Enterprise Linux 10 — versions 0:4.23.5-109.el10_2
- Red Hat Enterprise Linux 10.0 Extended Update Support — versions 0:4.21.3-114.el10_0.1
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8 — versions 0:4.19.4-16.el8_10
- Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support — versions 0:4.15.5-16.el8_6.1
- Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On — versions 0:4.15.5-16.el8_6.1
- Red Hat Enterprise Linux 8.8 Telecommunications Update Service — versions 0:4.17.5-7.el8_8.1
- Red Hat Enterprise Linux 8.8 Update Services For SAP Solutions — versions 0:4.17.5-7.el8_8.1
Weakness classification (CWE)
References
- access.redhat.com/security/cve/CVE-2026-2340 (Third Party Advisory, Mitigation, vdb-entry)
- bugzilla.redhat.com/show_bug.cgi (issue-tracking, Third Party Advisory, Issue Tracking)
- bugzilla.samba.org/show_bug.cgi (Issue Tracking, Vendor Advisory)
- access.redhat.com/errata/RHSA-2026:22963 (vendor-advisory)
- access.redhat.com/errata/RHSA-2026:25049 (vendor-advisory)
- access.redhat.com/errata/RHSA-2026:25979 (vendor-advisory)
- access.redhat.com/errata/RHSA-2026:22644 (vendor-advisory)
- access.redhat.com/errata/RHSA-2026:28057 (vendor-advisory)
- access.redhat.com/errata/RHSA-2026:28054 (vendor-advisory)
- access.redhat.com/errata/RHSA-2026:28055 (vendor-advisory)
Frequently asked questions
- What is CVE-2026-2340?
- CVE-2026-2340 is a medium-severity vulnerability in Samba, classified under Improper Handling of Insufficient Permissions or Privileges. CVSS score: 6.5/10. Published 2026-05-27.
- How severe is CVE-2026-2340?
- Medium severity. CVSS v3 base score is 6.5 out of 10.