CVE-2026-2340

MEDIUMPre-NVD 6.56.5
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to the CVSS score beside it.

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, GitHub Security Advisory, a secondary CVSS source

Also known asEUVD-2026-32312 (ENISA EUVD) · GHSA-m6w2-p258-gxqp (GitHub Security Advisories)Source: ENISA EUVD

6.5EG
EchelonGraph verdictMonitorRemediate within your standard update timelines (the SSVC decision on this page).
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.9%CVSS: 6.5Exploit: None knownExposed services: Not assessed

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
6.5MEDIUMmedium confidence
EG Risk
30
EG Risk 30/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity65% × 45%
Impact severity (EG Severity): CVSS 6.5 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.9% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at every mission impact level.
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: A fix is available. Apply it within your standard update timelines.
EPSS PROB
0.9%
EPSS %ILE
60th
KEV
Not listed

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (6.5): severity, escalated by confirmed exploitation. This CVE's 6.5 is its impact severity (EG Severity), not escalated.

EG Severity
6.5 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
0.9% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-24). FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Track at medium mission impactTrack at every mission impact level.CISA BOD 26-04: 60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Track at every mission impact level.

A fix is available. Apply it within your standard update timelines.

Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.

The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

May 27, 2026

Last Modified

October 15, 2026

Advisory Details (5)

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

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

https://bugzilla.samba.org/show_bug.cgi?id=15997
Red HatMentions a patch (unverified)

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
Red HatMentions a patch (unverified)

cve-details

https://access.redhat.com/security/cve/CVE-2026-2340
Red HatMentions a patch (unverified)

Affected: Red Hat Enterprise Linux 9.

https://access.redhat.com/errata/RHSA-2026:25049
Red HatMentions a patch (unverified)

Affected: Red Hat Enterprise Linux 10.

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

Patch Availability(24)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
ubuntuwinbind (2:4.23.6+dfsg-1ubuntu2.1) @ resolute2026-10-14ubuntu
redhatopenshift/ose-rhel-coreos-9:417.94.202609191027-02026-10-01redhat
redhatopenshift/ose-rhel-coreos-9:415.92.202609140326-02026-09-28redhat
redhatopenshift/ose-rhel-coreos-8:412.86.202609082051-02026-09-17redhat
redhatopenshift/ose-rhel-coreos-9:418.94.202609031320-02026-09-17redhat
redhatopenshift/ose-rhel-coreos-9:413.92.202609080414-02026-09-17redhat
redhatopenshift/ose-rhel-coreos-9:414.92.202609011250-02026-09-14redhat
redhatopenshift/ose-rhel-coreos-9:416.94.202609011112-02026-09-10redhat
redhatopenshift/ose-rhel-coreos-8:412.86.202608241157-02026-09-03redhat
redhatopenshift/ose-rhel-coreos-9:417.94.202608250221-02026-09-03redhat
redhatopenshift/ose-rhel-coreos-9:416.94.202608150307-02026-08-31redhat
redhatopenshift/ose-rhel-coreos-9:414.92.202608172040-02026-08-31redhat
redhatopenshift/ose-rhel-coreos-9:415.92.202608180329-02026-08-31redhat
redhatopenshift/ose-rhel-coreos-9:418.94.202608142238-02026-08-26redhat
redhatopenshift/ose-rhel-coreos-9:4.19.9.6.202606241344-02026-07-02redhat
redhatsamba-0:4.15.5-16.el8_6.12026-06-23redhat
redhatsamba-0:4.17.5-105.el9_2.52026-06-23redhat
redhatsamba-0:4.17.5-7.el8_8.12026-06-23redhat
redhatsamba-0:4.21.3-114.el10_0.12026-06-23redhat
redhatsamba-0:4.19.4-105.el9_4.42026-06-23redhat
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 rangeFix by version rangeDependents
samba—
  • 4.1.0 up to 4.22.10-r0: fixed in 4.22.10-r0
—
Alpine:v3.24(1)
PackageVulnerable rangeFix by version rangeDependents
samba—
  • 4.1.0 up to 4.23.8-r0: fixed in 4.23.8-r0
—
Debian:11(1)
PackageVulnerable rangeFix by version rangeDependents
samba2:4.13.13+dfsg-1~deb11u1 ... 2:4.13.5+dfsg-2 (8 versions)
  • every version up to 2:4.13.13+dfsg-1~deb11u8: fixed in 2:4.13.13+dfsg-1~deb11u8
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
samba2:4.17.10+dfsg-0+deb12u1 ... 2:4.17.9+dfsg-0+deb12u3~bpo11+1 (13 versions)
  • every version up to 2:4.17.12+dfsg-0+deb12u4: fixed in 2:4.17.12+dfsg-0+deb12u4
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
samba2:4.22.3+dfsg-4 ... 2:4.22.8+dfsg-0+deb13u1 (7 versions)
  • every version up to 2:4.22.8+dfsg-0+deb13u2: fixed in 2:4.22.8+dfsg-0+deb13u2
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
samba2:4.22.3+dfsg-4 ... 2:4.24.3+dfsg-1~bpo13+1 (30 versions)
  • every version up to 2:4.24.3+dfsg-1: fixed in 2:4.24.3+dfsg-1
—

Weakness Classification(1)

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

Additional Vendor Advisories

(5)

Data Freshness Timeline

(refreshed 7× in last 7d / 50× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. 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. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.

Showing the most recent 98 of 398 refreshes on record for this CVE.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. 2 repeat rows among the latest 100 are merged into the row they repeat. The 300 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-02 16:44 UTCEPSS rescoreEPSS 0.9% · 60th percentile
  2. 2026-11-01 16:34 UTCEPSS rescoreEPSS 0.9% · 60th percentile
  3. 2026-10-31 16:32 UTCEPSS rescoreEPSS 0.9% · 60th percentile
  4. 2026-10-30 16:34 UTCEPSS rescoreEPSS 0.9% · 60th percentile
  5. 2026-10-29 16:33 UTCEPSS rescoreEPSS 0.9% · 60th percentile
  6. 2026-10-28 16:32 UTCEPSS rescoreEPSS 0.9% · 60th percentile
  7. 2026-10-27 16:31 UTCEPSS rescoreEPSS 0.9% · 60th percentile
  8. 2026-10-26 16:31 UTCEPSS rescoreEPSS 0.9% · 60th percentile
  9. 2026-10-25 16:32 UTCEPSS rescoreEPSS 0.9% · 60th percentile
  10. 2026-10-25 14:41 UTCEG score recompute
  11. 2026-10-24 16:32 UTCEPSS rescoreEPSS 0.9% · 60th percentile
  12. 2026-10-23 16:31 UTCEPSS rescoreEPSS 0.9% · 60th percentile
  13. 2026-10-22 16:34 UTCEPSS rescoreEPSS 0.9% · 60th percentile
  14. 2026-10-21 16:32 UTCEPSS rescoreEPSS 0.9% · 60th percentile
  15. 2026-10-20 16:32 UTCEPSS rescoreEPSS 0.9% · 60th percentile
  16. 2026-10-19 16:31 UTCEPSS rescoreEPSS 0.9% · 60th percentile
  17. 2026-10-18 16:31 UTCEPSS rescoreEPSS 0.9% · 60th percentile
  18. 2026-10-18 03:54 UTCEG score recompute
  19. 2026-10-17 16:33 UTCEPSS rescoreEPSS 0.9% · 60th percentile
  20. 2026-10-16 16:41 UTCEPSS rescoreEPSS 0.9% · 60th percentile
  21. 2026-10-15 17:32 UTCEG score recompute
  22. 2026-10-15 17:32 UTCVendor advisory
  23. 2026-10-15 17:31 UTCGHSA enrichmentGHSA-m6w2-p258-gxqp · GitHub CVSS 6.5
  24. 2026-10-15 17:06 UTCEG score recompute
  25. 2026-10-15 17:06 UTCVendor advisory
Show 73 more
  1. 2026-10-15 17:05 UTCGHSA enrichmentGHSA-m6w2-p258-gxqp · GitHub CVSS 6.5
  2. 2026-10-15 16:31 UTCEPSS rescoreEPSS 0.9% · 60th percentile
  3. 2026-10-14 20:37 UTCEG score recompute
  4. 2026-10-14 20:37 UTCVendor advisory
  5. 2026-10-14 20:37 UTCGHSA enrichmentGHSA-m6w2-p258-gxqp · GitHub CVSS 6.5
  6. 2026-10-14 16:32 UTCEPSS rescoreEPSS 0.9% · 60th percentile
  7. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.9% · 59th percentile
  8. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.9% · 59th percentile
  9. 2026-10-12 16:21 UTCEG score recompute
  10. 2026-10-11 20:03 UTCEG score recompute
  11. 2026-10-11 17:16 UTCEG score recompute
  12. 2026-10-11 14:48 UTCEG score recompute
  13. 2026-10-11 13:48 UTCEPSS rescoreEPSS 0.9% · 59th percentile
  14. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.9% · 59th percentile
  15. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.9% · 59th percentile
  16. 2026-10-09 00:21 UTCEG score recompute
  17. 2026-10-09 00:21 UTCVendor advisory
  18. 2026-10-09 00:21 UTCGHSA enrichmentGHSA-m6w2-p258-gxqp · GitHub CVSS 6.5
  19. 2026-10-08 23:24 UTCEG score recompute
  20. 2026-10-08 23:24 UTCVendor advisory
  21. 2026-10-08 23:23 UTCGHSA enrichmentGHSA-m6w2-p258-gxqp · GitHub CVSS 6.5
  22. 2026-10-08 17:12 UTCEPSS rescoreEPSS 0.9% · 59th percentile
  23. 2026-10-07 23:47 UTCEPSS rescoreEPSS 0.9% · 59th percentile
  24. 2026-10-06 15:17 UTCEPSS rescoreEPSS 0.9% · 59th percentile
  25. 2026-10-05 17:42 UTCEPSS rescoreEPSS 0.9% · 59th percentile
  26. 2026-10-03 14:25 UTCEPSS rescoreEPSS 0.9% · 59th percentile
  27. 2026-10-01 19:49 UTCEPSS rescoreEPSS 0.9% · 59th percentile
  28. 2026-10-01 18:31 UTCEG score recompute
  29. 2026-10-01 18:31 UTCVendor advisory
  30. 2026-10-01 18:31 UTCGHSA enrichmentGHSA-m6w2-p258-gxqp · GitHub CVSS 6.5
  31. 2026-10-01 17:21 UTCEG score recompute
  32. 2026-10-01 17:21 UTCVendor advisory
  33. 2026-10-01 17:21 UTCGHSA enrichmentGHSA-m6w2-p258-gxqp · GitHub CVSS 6.5
  34. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.9% · 59th percentile
  35. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.9% · 59th percentile
  36. 2026-09-28 02:19 UTCEG score recompute
  37. 2026-09-28 02:19 UTCVendor advisory
  38. 2026-09-28 02:19 UTCGHSA enrichmentGHSA-m6w2-p258-gxqp · GitHub CVSS 6.5
  39. 2026-09-28 02:12 UTCEG score recompute
  40. 2026-09-28 02:12 UTCVendor advisory
  41. 2026-09-28 02:12 UTCGHSA enrichmentGHSA-m6w2-p258-gxqp · GitHub CVSS 6.5
  42. 2026-09-26 15:58 UTCEPSS rescoreEPSS 0.9% · 59th percentile
  43. 2026-09-26 00:26 UTCEPSS rescoreEPSS 0.9% · 59th percentile
  44. 2026-09-20 20:15 UTCEPSS rescoreEPSS 0.9% · 59th percentile
  45. 2026-09-18 19:27 UTCEPSS rescoreEPSS 0.9% · 59th percentile
  46. 2026-09-17 19:30 UTCEPSS rescoreEPSS 0.9% · 59th percentile
  47. 2026-09-17 19:28 UTCEG score recompute
  48. 2026-09-17 19:28 UTCVendor advisory
  49. 2026-09-17 19:28 UTCGHSA enrichmentGHSA-m6w2-p258-gxqp · GitHub CVSS 6.5
  50. 2026-09-17 19:12 UTCEG score recompute
  51. 2026-09-17 19:12 UTCVendor advisory
  52. 2026-09-17 19:11 UTCGHSA enrichmentGHSA-m6w2-p258-gxqp · GitHub CVSS 6.5
  53. 2026-09-17 13:29 UTCEG score recompute
  54. 2026-09-17 13:29 UTCVendor advisory
  55. 2026-09-17 13:29 UTCGHSA enrichmentGHSA-m6w2-p258-gxqp · GitHub CVSS 6.5
  56. 2026-09-17 12:53 UTCEG score recompute
  57. 2026-09-17 12:53 UTCVendor advisory
  58. 2026-09-17 12:53 UTCGHSA enrichmentGHSA-m6w2-p258-gxqp · GitHub CVSS 6.5
  59. 2026-09-17 09:32 UTCEG score recompute
  60. 2026-09-17 09:32 UTCVendor advisory
  61. 2026-09-17 09:32 UTCGHSA enrichmentGHSA-m6w2-p258-gxqp · GitHub CVSS 6.5
  62. 2026-09-17 08:35 UTCEG score recompute
  63. 2026-09-17 08:35 UTCVendor advisory
  64. 2026-09-17 08:35 UTCGHSA enrichmentGHSA-m6w2-p258-gxqp · GitHub CVSS 6.5
  65. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.9% · 59th percentile
  66. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.9% · 59th percentile
  67. 2026-09-14 13:38 UTCEG score recompute
  68. 2026-09-14 13:38 UTCVendor advisory
  69. 2026-09-14 13:38 UTCGHSA enrichmentGHSA-m6w2-p258-gxqp · GitHub CVSS 6.5
  70. 2026-09-14 13:11 UTCEG score recompute
  71. 2026-09-14 13:11 UTCVendor advisory
  72. 2026-09-14 13:11 UTCGHSA enrichmentGHSA-m6w2-p258-gxqp · GitHub CVSS 6.5
  73. 2026-09-14 09:24 UTCEG score recompute

Frequently asked(5)

What is CVE-2026-2340?
CVE-2026-2340 is a medium-severity vulnerability; its CVE record was 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 made public?
CVE-2026-2340 was made public on May 27, 2026: that is the date its CVE record's CNA, Red Hat, Inc., gives for when the vulnerability was made public. The CVE record itself was published on May 27, 2026. EchelonGraph's copy of the record carries a last-modified date of October 15, 2026; the record at its source may have been updated since.
Is CVE-2026-2340 actively exploited?
CVE-2026-2340 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.9% probability of exploitation in the next 30 days (60th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-2340?
CVE-2026-2340 has a CVSS base score of 6.5 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-2340?
A fix for CVE-2026-2340 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-2340 are linked in the Vendor Advisories panel on this page.

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