CVE-2026-6739

HIGHNVD 7.27.2—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.2 under NVD CVSS v3. EPSS exploit probability: 0.3%, top 83% of all CVEs by exploit prediction. GitHub Security Advisory enrichment pending alignment with NVD CVSS.

Triggered by: NVD CVSS baseline
Sources: epss, ghsa, nvd
7.2EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.2Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

Mattermost versions 11.6.x <= 11.6.1, 11.5.x <= 11.5.4, 10.11.x <= 10.11.15, 10.11.x <= 10.11.16 fail to require system-level permission when patching protected default system roles, which allows authenticated users with delegated user-management permissions to escalate privileges by altering built-in role permissions via the role patch API.. Mattermost Advisory ID: MMSA-2026-00656

CVSS v3
7.2
EG Score
7.2(medium)
EG Risk
33(Track)
EG Risk 33/100SSVC: 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
Severity72% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
17%
KEV
Not listed

Published

June 12, 2026

Last Modified

June 18, 2026

Advisory Details (1)

Auto-updated Jun 12, 2026
No patch confirmed yet.
generic

Security Updates

https://mattermost.com/security-updates

Vendor Advisories for CVE-2026-6739(1)

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

Affected Packages

(4 across 1 ecosystem)
Go(4)
PackageVulnerable rangeFixed inDependents
github.com/mattermost/mattermost-server11.6.011.6.1+incompatible—
github.com/mattermost/mattermost-server/v5———
github.com/mattermost/mattermost-server/v6———
github.com/mattermost/mattermost/server/v8—8.0.0-20260501142004-99b73d4c4acf—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 6× in last 7d / 39× 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 218 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2026-6739?
CVE-2026-6739 is a high vulnerability published on June 12, 2026. Mattermost versions 11.6.x <= 11.6.1, 11.5.x <= 11.5.4, 10.11.x <= 10.11.15, 10.11.x <= 10.11.16 fail to require system-level permission when patching protected default system roles, which allows authenticated users with delegated user-management permissions to escalate privileges by altering…
When was CVE-2026-6739 disclosed?
CVE-2026-6739 was first published in the National Vulnerability Database on June 12, 2026, with the most recent update on June 18, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-6739 actively exploited?
CVE-2026-6739 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 82.5% of all scored CVEs.
What is the CVSS score of CVE-2026-6739?
CVE-2026-6739 has a CVSS v3 base score of 7.2 (NVD).
How do I remediate CVE-2026-6739?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-6739, 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

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