CVE-2026-100550

MEDIUMPre-NVD 5.45.4—
EchelonGraph scoreHIGH confidence

Score 5.4 from GitHub Security Advisory published 2026-09-26. A secondary CVSS source baseline 5.4; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 3 sources updated this week
5.4EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.2%CVSS: 5.4Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

OpenClaw (npm package 'openclaw') before 2026.8.1 contains an access-control bypass in the Microsoft Teams integration. When groupPolicy is set to allowlist, a missing or unsupported configured access group produces a denied group-resolution result that is not rejected by the final message-admission check, so a Teams member who is not on the allowlist can still trigger the configured agent despite the administrator's group boundary. The impact depends on the conversations, tools, and data available to that agent. The issue is fixed in version 2026.8.1.

CVSS v3
5.4
EG Score
5.4MEDIUMhigh confidence
EG Risk
24
EG Risk 24/100CISA SSVC

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
Severity54% × 45%
Exploitation0% × 40%
Automatability0% × 15%
CISA SSVC: Track at every mission impact level.
Action: A fix is available. Apply it within your standard update timelines.
EPSS PROB
0.2%
EPSS %ILE
7th
KEV
Not listed

CISA SSVCTrack 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). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

September 26, 2026

Last Modified

September 28, 2026

Advisory Details (2)

Auto-updated Sep 26, 2026
Patch available. Sources: github.
generic Patch Available

OpenClaw before 2026.8.1 Authentication Bypass via Access Group | Advisories | VulnCheck

https://www.vulncheck.com/advisories/openclaw-before-2026.8.1-authentication-bypass-via-access-group
github Patch Available

Microsoft Teams access-group failures could admit unlisted senders · Advisory · openclaw/openclaw · GitHub

https://github.com/openclaw/openclaw/security/advisories/GHSA-8938-r7c6-54vq

Vendor Advisories for CVE-2026-100550(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 22× in last 7d / 28× 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. 2026-10-03 17:15 UTCEG score recompute
  2. 2026-10-03 17:15 UTCGHSA enrichment
  3. 2026-10-03 14:25 UTCEPSS rescore
  4. 2026-10-02 17:30 UTCEG score recompute
  5. 2026-10-02 17:30 UTCGHSA enrichment
  6. 2026-10-01 19:49 UTCEPSS rescore
  7. 2026-10-01 17:45 UTCGHSA enrichment
  8. 2026-09-30 18:00 UTCEG score recompute
  9. 2026-09-30 18:00 UTCGHSA enrichment
  10. 2026-09-30 15:02 UTCEPSS rescore
  11. 2026-09-29 18:14 UTCEG score recompute
  12. 2026-09-29 18:14 UTCGHSA enrichment
  13. 2026-09-29 15:20 UTCEPSS rescore
  14. 2026-09-28 18:22 UTCEG score recompute
  15. 2026-09-28 18:22 UTCGHSA enrichment
  16. 2026-09-28 17:52 UTCEG score recompute
  17. 2026-09-28 17:52 UTCGHSA enrichment
  18. 2026-09-28 15:32 UTCEG score recompute
  19. 2026-09-28 15:32 UTCGHSA enrichment
  20. 2026-09-28 13:50 UTCEPSS rescore
  21. 2026-09-28 02:59 UTCEG score recompute
  22. 2026-09-28 02:59 UTCGHSA enrichment
  23. 2026-09-27 03:14 UTCEG score recompute
  24. 2026-09-27 03:14 UTCGHSA enrichment
  25. 2026-09-26 15:58 UTCEPSS rescore
Show 3 more
  1. 2026-09-26 03:28 UTCEG score recompute
  2. 2026-09-26 02:32 UTCEG score recompute
  3. 2026-09-26 02:29 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-100550?
CVE-2026-100550 is a medium vulnerability published on September 26, 2026. OpenClaw (npm package 'openclaw') before 2026.8.1 contains an access-control bypass in the Microsoft Teams integration. When groupPolicy is set to allowlist, a missing or unsupported configured access group produces a denied group-resolution result that is not rejected by the final…
When was CVE-2026-100550 disclosed?
CVE-2026-100550 was first published on September 26, 2026, with the most recent update on September 28, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-100550 actively exploited?
CVE-2026-100550 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.2% probability of exploitation in the next 30 days (7th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-100550?
CVE-2026-100550 has a CVSS base score of 5.4 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-100550?
A fix for CVE-2026-100550 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-100550 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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