CVE-2026-55366

CRITICALPre-NVD 9.89.8—
EchelonGraph scoreHIGH confidence

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2026-09-15. CISA-ADP (Vulnrichment) CVSS v3.1 baseline 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cisa-adp, epss, ghsa
Trending — 5 sources updated this week
9.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 9.8Exploit: None knownExposed: 0

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

In IP Multimedia Subsystem, there is a possible authentication bypass due to a logic error in the code. This could lead to remote escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation.

CVSS v3
9.8
EG Score
9.8(high)
EG Risk
59(Track)
EG Risk 59/100SSVC: 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
Severity98% × 45%
Exploitation0% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
30%
KEV
Not listed

Published

September 15, 2026

Last Modified

September 17, 2026

Advisory Details (1)

Auto-updated Sep 17, 2026
No patch confirmed yet.
generic

Pixel Update Bulletin—September 2026  |  Android Open Source Project

https://source.android.com/docs/security/bulletin/pixel/2026/2026-09-01

Vendor Advisories for CVE-2026-55366(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 36× 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. 2026-09-19 21:43 UTCGHSA enrichment
  2. 2026-09-19 17:53 UTCEG score recompute
  3. 2026-09-19 17:53 UTCGHSA enrichment
  4. 2026-09-19 14:03 UTCGHSA enrichment
  5. 2026-09-19 10:13 UTCGHSA enrichment
  6. 2026-09-19 06:24 UTCGHSA enrichment
  7. 2026-09-19 02:35 UTCGHSA enrichment
  8. 2026-09-18 22:45 UTCEG score recompute
  9. 2026-09-18 22:45 UTCGHSA enrichment
  10. 2026-09-18 19:28 UTCEPSS rescore
  11. 2026-09-18 18:56 UTCGHSA enrichment
  12. 2026-09-18 15:06 UTCGHSA enrichment
  13. 2026-09-18 11:17 UTCGHSA enrichment
  14. 2026-09-18 07:27 UTCGHSA enrichment
  15. 2026-09-18 03:38 UTCGHSA enrichment
  16. 2026-09-17 23:48 UTCGHSA enrichment
  17. 2026-09-17 19:41 UTCEG score recompute
  18. 2026-09-17 19:41 UTCGHSA enrichment
  19. 2026-09-17 19:31 UTCEPSS rescore
  20. 2026-09-17 15:52 UTCGHSA enrichment
  21. 2026-09-17 12:02 UTCGHSA enrichment
  22. 2026-09-17 08:12 UTCGHSA enrichment
  23. 2026-09-17 04:21 UTCGHSA enrichment
  24. 2026-09-17 04:06 UTCGHSA enrichment
  25. 2026-09-17 03:13 UTCGHSA enrichment
Show 11 more
  1. 2026-09-16 23:24 UTCGHSA enrichment
  2. 2026-09-16 19:34 UTCEG score recompute
  3. 2026-09-16 19:34 UTCGHSA enrichment
  4. 2026-09-16 16:55 UTCGHSA enrichment
  5. 2026-09-16 15:45 UTCEG score recompute▲ 9.80
  6. 2026-09-16 15:45 UTCGHSA enrichment
  7. 2026-09-16 15:44 UTCMITRE cvelistV5CVSS v3 → 9.8 · severity → CRITICAL
  8. 2026-09-16 14:08 UTCEPSS rescore
  9. 2026-09-15 19:32 UTCNVD update
  10. 2026-09-15 18:39 UTCEG score recompute
  11. 2026-09-15 18:37 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-55366?
CVE-2026-55366 is a critical vulnerability published on September 15, 2026. In IP Multimedia Subsystem, there is a possible authentication bypass due to a logic error in the code. This could lead to remote escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation.
When was CVE-2026-55366 disclosed?
CVE-2026-55366 was first published in the National Vulnerability Database on September 15, 2026, with the most recent update on September 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-55366 actively exploited?
CVE-2026-55366 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 70.1% of all scored CVEs.
What is the CVSS score of CVE-2026-55366?
CVE-2026-55366 has a CVSS v3.1 base score of 9.8 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-55366?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-55366, 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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