CVE-2026-77900

CRITICALPre-NVD 9.89.8—
EchelonGraph scoreHIGH confidence

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2026-10-09. A secondary CVSS source baseline 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 5 sources updated this week
9.8EG
EchelonGraph verdictPlan mitigationSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.5%CVSS: 9.8Exploit: None knownExposed services: Not assessed

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

Missing authentication for critical function in Azure App Service allows an unauthorized attacker to execute code over a network.

CVSS v3
9.8
EG Score
9.8CRITICALhigh confidence
EG Risk
59
EG Risk 59/100CISA 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
Severity98% × 45%
Exploitation0% × 40%
Automatability100% × 15%
CISA SSVC: Track at low or medium mission impact; Attend at high (mission-essential systems).
Action: No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines at low or medium mission impact and sooner than that at high, and watch the vendor's advisory for the fix.
EPSS PROB
0.5%
EPSS %ILE
40th
KEV
Not listed

CISA SSVCTrack at low or medium mission impact; Attend at high (mission-essential systems).

No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines at low or medium mission impact and sooner than that at high, and watch the vendor's advisory for the fix.

Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact total (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

October 8, 2026

Last Modified

October 9, 2026

Advisory Details (1)

Auto-updated Oct 9, 2026
No fix on record yet. Sources: microsoft.
microsoftMentions a patch (unverified)

Security Update Guide - Microsoft Security Response Center

Security Update Guide - Microsoft Security Response Center. Patch available via Microsoft Security Update

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-77900

Vendor Advisories for CVE-2026-77900(2)

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 26× in last 7d / 26× 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. 2026-10-10 00:47 UTCVendor advisory
  2. 2026-10-10 00:46 UTCGHSA enrichment
  3. 2026-10-09 20:54 UTCEG score recompute
  4. 2026-10-09 20:54 UTCVendor advisory
  5. 2026-10-09 20:54 UTCGHSA enrichment
  6. 2026-10-09 20:07 UTCEPSS rescore
  7. 2026-10-09 17:01 UTCVendor advisory
  8. 2026-10-09 17:01 UTCGHSA enrichment
  9. 2026-10-09 15:33 UTCEG score recompute
  10. 2026-10-09 15:33 UTCVendor advisory
  11. 2026-10-09 15:33 UTCGHSA enrichment
  12. 2026-10-09 15:00 UTCEG score recompute
  13. 2026-10-09 15:00 UTCVendor advisory
  14. 2026-10-09 14:59 UTCGHSA enrichment
  15. 2026-10-09 11:17 UTCVendor advisory
  16. 2026-10-09 11:17 UTCGHSA enrichment
  17. 2026-10-09 07:09 UTCVendor advisory
  18. 2026-10-09 07:08 UTCGHSA enrichment
  19. 2026-10-09 03:15 UTCEG score recompute
  20. 2026-10-09 03:15 UTCVendor advisory
  21. 2026-10-09 03:15 UTCGHSA enrichment
  22. 2026-10-08 23:22 UTCEG score recompute
  23. 2026-10-08 23:22 UTCVendor advisory
  24. 2026-10-08 22:29 UTCEG score recompute
  25. 2026-10-08 22:29 UTCVendor advisory
Show 1 more
  1. 2026-10-08 22:28 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-77900?
CVE-2026-77900 is a critical vulnerability published on October 8, 2026. Missing authentication for critical function in Azure App Service allows an unauthorized attacker to execute code over a network.
When was CVE-2026-77900 disclosed?
CVE-2026-77900 was first published on October 8, 2026, with the most recent update on October 9, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-77900 actively exploited?
CVE-2026-77900 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.5% probability of exploitation in the next 30 days (40th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-77900?
CVE-2026-77900 has a CVSS base score of 9.8 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-77900?
No fix for CVE-2026-77900 is confirmed yet. Until one is published, restrict network exposure of the affected system or apply the vendor's mitigation — for example, keep it off the internet or limit it to trusted networks — and watch the vendor's advisory for the fix. The vendor advisories EchelonGraph has for CVE-2026-77900 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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