CVE-2026-21391

CRITICALPre-NVD 9.59.5—
EchelonGraph scoreMEDIUM confidence

This critical-severity CVE scores 9.5 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.4%, top 62% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
Trending — 4 sources updated this week
9.5EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 9.5Exploit: None knownExposed: 0

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

An improper validation vulnerability exists within PingAM where a well-crafted request allows arbitrary or protected ID Token claims to be set or overridden. In certain configurations this could allow an attacker to bypass authentication controls via spoofing leading to privilege escalation or impersonation.

CVSS v3
9.5
EG Score
9.5(medium)
EG Risk
43(Track)
EG Risk 43/100SSVC: 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
Severity95% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
38%
KEV
Not listed

Published

September 14, 2026

Last Modified

September 18, 2026

Advisory Details (1)

Auto-updated Sep 14, 2026
No patch confirmed yet.
generic
https://support.pingidentity.com/s/article/PingAM-Security-Advisory-202603

Vendor Advisories for CVE-2026-21391(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 49× in last 7d / 49× 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 20:59 UTCGHSA enrichment
  2. 2026-09-19 17:21 UTCEG score recompute
  3. 2026-09-19 17:21 UTCGHSA enrichment
  4. 2026-09-19 13:43 UTCGHSA enrichment
  5. 2026-09-19 10:05 UTCGHSA enrichment
  6. 2026-09-19 06:27 UTCGHSA enrichment
  7. 2026-09-19 02:49 UTCGHSA enrichment
  8. 2026-09-18 23:10 UTCGHSA enrichment
  9. 2026-09-18 19:33 UTCEG score recompute
  10. 2026-09-18 19:33 UTCGHSA enrichment
  11. 2026-09-18 19:27 UTCEPSS rescore
  12. 2026-09-18 18:11 UTCGHSA enrichment
  13. 2026-09-18 14:24 UTCGHSA enrichment
  14. 2026-09-18 10:46 UTCGHSA enrichment
  15. 2026-09-18 07:08 UTCGHSA enrichment
  16. 2026-09-18 03:30 UTCGHSA enrichment
  17. 2026-09-17 23:51 UTCGHSA enrichment
  18. 2026-09-17 19:33 UTCEG score recompute
  19. 2026-09-17 19:33 UTCGHSA enrichment
  20. 2026-09-17 13:58 UTCGHSA enrichment
  21. 2026-09-17 10:20 UTCGHSA enrichment
  22. 2026-09-17 06:42 UTCGHSA enrichment
  23. 2026-09-17 02:58 UTCGHSA enrichment
  24. 2026-09-16 23:21 UTCGHSA enrichment
  25. 2026-09-16 19:43 UTCGHSA enrichment
Show 24 more
  1. 2026-09-16 16:05 UTCEG score recompute
  2. 2026-09-16 16:05 UTCGHSA enrichment
  3. 2026-09-16 14:07 UTCEPSS rescore
  4. 2026-09-16 12:26 UTCGHSA enrichment
  5. 2026-09-16 08:49 UTCEG score recompute
  6. 2026-09-16 08:49 UTCGHSA enrichment
  7. 2026-09-16 05:15 UTCEPSS rescore
  8. 2026-09-16 04:23 UTCGHSA enrichment
  9. 2026-09-16 00:36 UTCGHSA enrichment
  10. 2026-09-15 20:48 UTCGHSA enrichment
  11. 2026-09-15 16:49 UTCGHSA enrichment
  12. 2026-09-15 13:11 UTCGHSA enrichment
  13. 2026-09-15 09:34 UTCGHSA enrichment
  14. 2026-09-15 05:56 UTCGHSA enrichment
  15. 2026-09-15 02:18 UTCGHSA enrichment
  16. 2026-09-14 22:37 UTCGHSA enrichment
  17. 2026-09-14 18:59 UTCGHSA enrichment
  18. 2026-09-14 15:21 UTCEG score recompute
  19. 2026-09-14 15:21 UTCGHSA enrichment
  20. 2026-09-14 14:40 UTCEG score recompute
  21. 2026-09-14 14:40 UTCGHSA enrichment
  22. 2026-09-14 12:26 UTCEG score recompute
  23. 2026-09-14 11:25 UTCEG score recompute
  24. 2026-09-14 11:24 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-21391?
CVE-2026-21391 is a critical vulnerability published on September 14, 2026. An improper validation vulnerability exists within PingAM where a well-crafted request allows arbitrary or protected ID Token claims to be set or overridden. In certain configurations this could allow an attacker to bypass authentication controls via spoofing leading to privilege escalation or…
When was CVE-2026-21391 disclosed?
CVE-2026-21391 was first published in the National Vulnerability Database on September 14, 2026, with the most recent update on September 18, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-21391 actively exploited?
CVE-2026-21391 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 61.8% of all scored CVEs.
What is the CVSS score of CVE-2026-21391?
CVE-2026-21391 has a CVSS v3 base score of 9.5 (NVD).
How do I remediate CVE-2026-21391?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-21391, 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-2026-21391

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