CVE-2026-58066

CRITICALPre-NVD 9.89.8—
EchelonGraph scoreHIGH confidence

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2026-07-30. a secondary CVSS source baseline 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 4 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.

Rocket.Chat's SAML SSO before versions 8.7.0, 8.6.1, 8.5.2, 8.4.5, 8.3.7, 8.2.7, 8.1.7, 8.0.8, and 7.10.14 verified XML signatures but did not bind the validated signature to samlp:Response / saml:Assertion. An attacker could submit a wrapped document carrying forged identity attributes alongside any valid signature made by the trusted IdP certificate, and log in as an arbitrary user.

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
11%
KEV
Not listed

Published

July 30, 2026

Last Modified

July 31, 2026

Advisory Details (2)

Auto-updated Jul 31, 2026
Patch available. Sources: github_pr.
generic

HackerOne

https://hackerone.com/reports/3827674
github_pr Patch Available

fix: imported fixes 07-08-2026

Patch available: RocketChat/Rocket.Chat 8.7.0-rc.0 (PR #41233 merged 2026-07-08)

https://github.com/RocketChat/Rocket.Chat/pull/41233

Vendor Advisories for CVE-2026-58066(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 24× in last 7d / 24× 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. 2026-07-31 19:29 UTCGHSA enrichment
  2. 2026-07-31 15:37 UTCGHSA enrichment
  3. 2026-07-31 11:51 UTCGHSA enrichment
  4. 2026-07-31 08:05 UTCGHSA enrichment
  5. 2026-07-31 04:19 UTCEG score recompute
  6. 2026-07-31 04:19 UTCGHSA enrichment
  7. 2026-07-31 04:08 UTCEG score recompute
  8. 2026-07-31 04:07 UTCGHSA enrichment
  9. 2026-07-31 03:10 UTCGHSA enrichment
  10. 2026-07-30 23:24 UTCGHSA enrichment
  11. 2026-07-30 19:37 UTCGHSA enrichment
  12. 2026-07-30 18:45 UTCEG score recompute
  13. 2026-07-30 18:44 UTCGHSA enrichment
  14. 2026-07-30 16:28 UTCEPSS rescore
  15. 2026-07-30 14:32 UTCEG score recompute
  16. 2026-07-30 14:31 UTCGHSA enrichment
  17. 2026-07-30 13:21 UTCEG score recompute
  18. 2026-07-30 13:21 UTCGHSA enrichment
  19. 2026-07-30 10:24 UTCEG score recompute
  20. 2026-07-30 10:23 UTCGHSA enrichment
  21. 2026-07-30 06:37 UTCEG score recompute
  22. 2026-07-30 06:37 UTCGHSA enrichment
  23. 2026-07-30 06:19 UTCEG score recompute
  24. 2026-07-30 06:18 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-58066?
CVE-2026-58066 is a critical vulnerability published on July 30, 2026. Rocket.Chat's SAML SSO before versions 8.7.0, 8.6.1, 8.5.2, 8.4.5, 8.3.7, 8.2.7, 8.1.7, 8.0.8, and 7.10.14 verified XML signatures but did not bind the validated signature to samlp:Response / saml:Assertion. An attacker could submit a wrapped document carrying forged identity attributes alongside…
When was CVE-2026-58066 disclosed?
CVE-2026-58066 was first published in the National Vulnerability Database on July 30, 2026, with the most recent update on July 31, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-58066 actively exploited?
CVE-2026-58066 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 88.7% of all scored CVEs.
What is the CVSS score of CVE-2026-58066?
CVE-2026-58066 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2026-58066?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-58066, 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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