CVE-2026-82920

MEDIUMPre-NVD 5.55.5—
EchelonGraph scoreHIGH confidence

Score 5.5 from GitHub Security Advisory published 2026-09-14. a secondary CVSS source baseline 5.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 3 sources updated this week
5.5EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 5.5Exploit: None knownExposed: 0

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

Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7 fail to enforce authorization boundaries on the access control policy update endpoint which allows a channel or team administrator to detach a system-assigned ABAC parent policy via a crafted PUT /api/v4/access_control_policies request with an empty imports list.. Mattermost Advisory ID: MMSA-2026-00724

CVSS v3
5.5
EG Score
5.5(high)
EG Risk
25(Track)
EG Risk 25/100SSVC: 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
Severity55% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
15%
KEV
Not listed

Published

September 14, 2026

Last Modified

September 16, 2026

Advisory Details (1)

Auto-updated Sep 14, 2026
No patch confirmed yet.
generic

Security Updates

https://mattermost.com/security-updates

Vendor Advisories for CVE-2026-82920(1)

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

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 21× in last 7d / 36× 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.

  1. 2026-09-25 03:53 UTCEG score recompute
  2. 2026-09-25 03:52 UTCGHSA enrichment
  3. 2026-09-24 14:04 UTCEPSS rescore
  4. 2026-09-24 05:50 UTCEG score recompute
  5. 2026-09-24 05:50 UTCGHSA enrichment
  6. 2026-09-23 17:54 UTCEPSS rescore
  7. 2026-09-23 07:48 UTCEG score recompute
  8. 2026-09-23 07:48 UTCGHSA enrichment
  9. 2026-09-22 16:01 UTCEPSS rescore
  10. 2026-09-22 09:45 UTCEG score recompute
  11. 2026-09-22 09:45 UTCGHSA enrichment
  12. 2026-09-21 21:09 UTCEPSS rescore
  13. 2026-09-21 11:43 UTCEG score recompute
  14. 2026-09-21 11:43 UTCGHSA enrichment
  15. 2026-09-20 20:16 UTCEPSS rescore
  16. 2026-09-20 13:40 UTCEG score recompute
  17. 2026-09-20 13:40 UTCGHSA enrichment
  18. 2026-09-19 15:38 UTCEG score recompute
  19. 2026-09-19 15:38 UTCGHSA enrichment
  20. 2026-09-18 19:28 UTCEPSS rescore
  21. 2026-09-18 17:36 UTCGHSA enrichment
  22. 2026-09-17 19:33 UTCEG score recompute
  23. 2026-09-17 19:33 UTCGHSA enrichment
  24. 2026-09-16 19:36 UTCGHSA enrichment
  25. 2026-09-16 17:56 UTCEG score recompute
Show 11 more
  1. 2026-09-16 17:56 UTCGHSA enrichment
  2. 2026-09-16 14:08 UTCEPSS rescore
  3. 2026-09-16 05:15 UTCEPSS rescore
  4. 2026-09-15 18:28 UTCGHSA enrichment
  5. 2026-09-14 20:25 UTCEG score recompute
  6. 2026-09-14 20:24 UTCGHSA enrichment
  7. 2026-09-14 19:30 UTCEG score recompute
  8. 2026-09-14 19:30 UTCGHSA enrichment
  9. 2026-09-14 14:30 UTCEG score recompute
  10. 2026-09-14 14:05 UTCEG score recompute
  11. 2026-09-14 14:04 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-82920?
CVE-2026-82920 is a medium vulnerability published on September 14, 2026. Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7 fail to enforce authorization boundaries on the access control policy update endpoint which allows a channel or team administrator to detach a system-assigned ABAC parent policy via a crafted PUT /api/v4/accesscontrolpolicies…
When was CVE-2026-82920 disclosed?
CVE-2026-82920 was first published in the National Vulnerability Database on September 14, 2026, with the most recent update on September 16, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-82920 actively exploited?
CVE-2026-82920 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 84.8% of all scored CVEs.
What is the CVSS score of CVE-2026-82920?
CVE-2026-82920 has a CVSS v3 base score of 5.5 (NVD).
How do I remediate CVE-2026-82920?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-82920, 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

Explore the affected products and dependency analysis for CVE-2026-82920

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