CVE-2026-2340

MEDIUMPre-NVD 6.56.5—
EchelonGraph scoreMEDIUM confidence

Score 6.5 from GitHub Security Advisory published 2026-05-27. a secondary CVSS source baseline 6.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — Patch released this week
6.5EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 6.5Exploit: None knownExposed: 0

A fix is available — apply it.

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.

CVSS v3
6.5
EG Score
6.5(medium)
EG Risk
30(Track)
EG Risk 30/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity65% × 45%
Exploitation1% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
1%
EPSS %ILE
59%
KEV
Not listed

Published

May 27, 2026

Last Modified

September 17, 2026

Advisory Details (5)

Auto-updated Jun 12, 2026
Patch available. Sources: redhat.
generic

15997 – (CVE-2026-2340) [SECURITY] CVE-2026-2340 vfs_worm does not block file overwrite

https://bugzilla.samba.org/show_bug.cgi?id=15997
redhat Patch Available

2447318 – (CVE-2026-2340) CVE-2026-2340 samba: vfs_worm does not block directory modification

Affected: Red Hat Enterprise Linux 10

https://bugzilla.redhat.com/show_bug.cgi?id=2447318
redhat Patch Available

cve-details

https://access.redhat.com/security/cve/CVE-2026-2340
redhat Patch Available

Affected: Red Hat Enterprise Linux 9.

https://access.redhat.com/errata/RHSA-2026:25049
redhat Patch Available

Affected: Red Hat Enterprise Linux 10.

https://access.redhat.com/errata/RHSA-2026:22963

Vendor Advisories for CVE-2026-2340(19)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(20)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatrhcos-418.94.202609031320-02026-09-17redhat
ubuntuwinbind (2:4.23.6+dfsg-1ubuntu2.1) @ resolute2026-09-17ubuntu
redhatrhcos-414.92.202609011250-02026-09-14redhat
redhatrhcos-416.94.202609011112-02026-09-10redhat
redhatrhcos-417.94.202608250221-02026-09-03redhat
redhatrhcos-412.86.202608241157-02026-09-03redhat
redhatrhcos-415.92.202608180329-02026-08-31redhat
redhatrhcos-414.92.202608172040-02026-08-31redhat
redhatrhcos-416.94.202608150307-02026-08-31redhat
redhatrhcos-418.94.202608142238-02026-08-26redhat
redhatrhcos-4.19.9.6.202606241344-02026-07-02redhat
redhatsamba-0:4.15.5-16.el8_6.12026-06-23redhat
redhatsamba-0:4.19.4-105.el9_4.42026-06-23redhat
redhatsamba-0:4.17.5-7.el8_8.12026-06-23redhat
redhatsamba-0:4.21.3-114.el10_0.12026-06-23redhat
redhatsamba-0:4.17.5-105.el9_2.52026-06-23redhat
redhatsamba-0:4.21.3-14.el9_6.12026-06-15redhat
redhatsamba-0:4.23.5-10.el9_82026-06-10redhat
redhatsamba-0:4.23.5-109.el10_22026-06-03redhat
redhatsamba-0:4.19.4-16.el8_102026-06-03redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(6 across 6 ecosystems)
Alpine:v3.23(1)
PackageVulnerable rangeFixed inDependents
samba—4.22.10-r0—
Alpine:v3.24(1)
PackageVulnerable rangeFixed inDependents
samba—4.23.8-r0—
Debian:11(1)
PackageVulnerable rangeFixed inDependents
samba2:4.13.13+dfsg-1~deb11u1 ... 2:4.13.5+dfsg-2 (8 versions)2:4.13.13+dfsg-1~deb11u8—
Debian:12(1)
PackageVulnerable rangeFixed inDependents
samba2:4.17.10+dfsg-0+deb12u1 ... 2:4.17.9+dfsg-0+deb12u3~bpo11+1 (13 versions)2:4.17.12+dfsg-0+deb12u4—
Debian:13(1)
PackageVulnerable rangeFixed inDependents
samba2:4.22.3+dfsg-4 ... 2:4.22.8+dfsg-0+deb13u1 (7 versions)2:4.22.8+dfsg-0+deb13u2—
Debian:14(1)
PackageVulnerable rangeFixed inDependents
samba2:4.22.3+dfsg-4 ... 2:4.24.3+dfsg-1~bpo13+1 (30 versions)2:4.24.3+dfsg-1—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Additional Vendor Advisories

(3)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

(refreshed 34× in last 7d / 111× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

Showing the most recent 100 of 330 total refreshes for this CVE.

  1. 2026-09-18 19:28 UTCEPSS rescore
  2. 2026-09-18 19:27 UTCEPSS rescore
  3. 2026-09-17 19:30 UTCEPSS rescore
  4. 2026-09-17 19:28 UTCEG score recompute
  5. 2026-09-17 19:28 UTCVendor advisory
  6. 2026-09-17 19:28 UTCGHSA enrichment
  7. 2026-09-17 19:12 UTCEG score recompute
  8. 2026-09-17 19:12 UTCVendor advisory
  9. 2026-09-17 19:11 UTCGHSA enrichment
  10. 2026-09-17 13:29 UTCEG score recompute
  11. 2026-09-17 13:29 UTCVendor advisory
  12. 2026-09-17 13:29 UTCGHSA enrichment
  13. 2026-09-17 12:53 UTCEG score recompute
  14. 2026-09-17 12:53 UTCVendor advisory
  15. 2026-09-17 12:53 UTCGHSA enrichment
  16. 2026-09-17 09:32 UTCEG score recompute
  17. 2026-09-17 09:32 UTCVendor advisory
  18. 2026-09-17 09:32 UTCGHSA enrichment
  19. 2026-09-17 08:35 UTCEG score recompute
  20. 2026-09-17 08:35 UTCVendor advisory
  21. 2026-09-17 08:35 UTCGHSA enrichment
  22. 2026-09-16 14:08 UTCEPSS rescore
  23. 2026-09-16 05:15 UTCEPSS rescore
  24. 2026-09-14 13:38 UTCEG score recompute
  25. 2026-09-14 13:38 UTCVendor advisory
Show 75 more
  1. 2026-09-14 13:38 UTCGHSA enrichment
  2. 2026-09-14 13:11 UTCEG score recompute
  3. 2026-09-14 13:11 UTCVendor advisory
  4. 2026-09-14 13:11 UTCGHSA enrichment
  5. 2026-09-14 09:24 UTCEG score recompute
  6. 2026-09-14 09:24 UTCVendor advisory
  7. 2026-09-14 09:24 UTCGHSA enrichment
  8. 2026-09-13 16:47 UTCEPSS rescore
  9. 2026-09-12 15:01 UTCEPSS rescore
  10. 2026-09-11 14:52 UTCEPSS rescore
  11. 2026-09-10 10:38 UTCEG score recompute
  12. 2026-09-10 10:38 UTCVendor advisory
  13. 2026-09-10 10:38 UTCGHSA enrichment
  14. 2026-09-10 10:00 UTCEG score recompute
  15. 2026-09-10 10:00 UTCVendor advisory
  16. 2026-09-10 10:00 UTCGHSA enrichment
  17. 2026-09-10 09:34 UTCEPSS rescore
  18. 2026-09-08 22:00 UTCEPSS rescore
  19. 2026-09-07 16:01 UTCEPSS rescore
  20. 2026-09-06 13:47 UTCEPSS rescore
  21. 2026-09-06 13:47 UTCEPSS rescore
  22. 2026-09-04 05:06 UTCEPSS rescore
  23. 2026-09-03 15:32 UTCEG score recompute
  24. 2026-09-03 15:32 UTCVendor advisory
  25. 2026-09-03 15:32 UTCGHSA enrichment
  26. 2026-09-03 14:35 UTCEG score recompute
  27. 2026-09-03 14:35 UTCVendor advisory
  28. 2026-09-03 14:35 UTCGHSA enrichment
  29. 2026-09-03 13:19 UTCEG score recompute
  30. 2026-09-03 13:19 UTCVendor advisory
  31. 2026-09-03 13:19 UTCGHSA enrichment
  32. 2026-09-03 12:29 UTCEG score recompute
  33. 2026-09-03 12:29 UTCVendor advisory
  34. 2026-09-03 12:29 UTCGHSA enrichment
  35. 2026-09-02 14:11 UTCEPSS rescore
  36. 2026-09-01 13:53 UTCEPSS rescore
  37. 2026-09-01 04:39 UTCEPSS rescore
  38. 2026-09-01 04:39 UTCEPSS rescore
  39. 2026-08-31 18:36 UTCEG score recompute
  40. 2026-08-31 18:36 UTCVendor advisory
  41. 2026-08-31 18:36 UTCGHSA enrichment
  42. 2026-08-31 17:48 UTCEG score recompute
  43. 2026-08-31 17:48 UTCVendor advisory
  44. 2026-08-31 17:47 UTCGHSA enrichment
  45. 2026-08-31 16:40 UTCVendor advisory
  46. 2026-08-31 16:40 UTCGHSA enrichment
  47. 2026-08-31 03:20 UTCEG score recompute
  48. 2026-08-31 03:20 UTCVendor advisory
  49. 2026-08-31 03:20 UTCGHSA enrichment
  50. 2026-08-31 02:34 UTCEG score recompute
  51. 2026-08-31 02:34 UTCVendor advisory
  52. 2026-08-31 02:34 UTCGHSA enrichment
  53. 2026-08-30 19:17 UTCEPSS rescore
  54. 2026-08-30 01:22 UTCEPSS rescore
  55. 2026-08-28 21:41 UTCEPSS rescore
  56. 2026-08-27 14:25 UTCEPSS rescore
  57. 2026-08-26 17:44 UTCVendor advisory
  58. 2026-08-26 17:44 UTCGHSA enrichment
  59. 2026-08-26 16:23 UTCEG score recompute
  60. 2026-08-26 16:23 UTCVendor advisory
  61. 2026-08-26 16:23 UTCGHSA enrichment
  62. 2026-08-26 14:46 UTCEPSS rescore
  63. 2026-08-26 13:43 UTCEG score recompute
  64. 2026-08-26 13:43 UTCVendor advisory
  65. 2026-08-26 13:43 UTCGHSA enrichment
  66. 2026-08-25 13:49 UTCEPSS rescore
  67. 2026-08-25 06:19 UTCEG score recompute
  68. 2026-08-25 06:19 UTCVendor advisory
  69. 2026-08-25 06:19 UTCGHSA enrichment
  70. 2026-08-24 14:17 UTCEPSS rescore
  71. 2026-08-23 15:46 UTCEG score recompute
  72. 2026-08-23 15:46 UTCVendor advisory
  73. 2026-08-23 15:46 UTCGHSA enrichment
  74. 2026-08-23 00:19 UTCEPSS rescore
  75. 2026-08-21 23:49 UTCEPSS rescore

Frequently asked(5)

What is CVE-2026-2340?
CVE-2026-2340 is a medium vulnerability published on May 27, 2026. 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…
When was CVE-2026-2340 disclosed?
CVE-2026-2340 was first published in the National Vulnerability Database on May 27, 2026, with the most recent update on September 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-2340 actively exploited?
CVE-2026-2340 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1% probability of exploitation in the next 30 days, which ranks it in the top 40.7% of all scored CVEs.
What is the CVSS score of CVE-2026-2340?
CVE-2026-2340 has a CVSS v3 base score of 6.5 (NVD).
How do I remediate CVE-2026-2340?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-2340, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-2340

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