CVE-2026-82843

CRITICALPre-NVD 9.09.0—
EchelonGraph scoreHIGH confidence

Score 9.0 from GitHub Security Advisory (severity: CRITICAL) published 2026-09-23. CISA-ADP (Vulnrichment) CVSS v3.1 baseline 9.0; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cisa-adp, epss, ghsa
Trending — 5 sources updated this week
9.0EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 9.0Exploit: None knownExposed: 0

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

The WP OAuth Server ( Login with WordPress ) WordPress plugin before 6.4.0 does not bind the OpenID Connect identity assertion it issues to the authorization grant being exchanged, returning instead the assertion belonging to whichever user authenticated most recently, which allows users with the Subscriber role and above to obtain a validly signed identity assertion for another user, including an administrator, and authenticate as them at any application that uses the site for single sign-on.

CVSS v3
9.0
EG Score
9.0(high)
EG Risk
41(Track)
EG Risk 41/100SSVC: 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
Severity90% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
7%
KEV
Not listed

Published

September 23, 2026

Last Modified

September 24, 2026

Advisory Details (1)

Auto-updated Sep 23, 2026
🔬 Proof of concept available. No patch confirmed yet.
generic🟡 PoC Available

WP OAuth Server < 6.4.0 – Subscriber+ Cross-User Account Takeover via OIDC ID Token Substitution | CVE 2026-82843 | Plugin Vulnerabilities

https://wpscan.com/vulnerability/45bc7096-5d04-4fe6-a332-31aed507a3a0/

Vendor Advisories for CVE-2026-82843(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 23× in last 7d / 23× 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. 2026-09-25 07:49 UTCGHSA enrichment
  2. 2026-09-25 03:35 UTCGHSA enrichment
  3. 2026-09-24 23:21 UTCGHSA enrichment
  4. 2026-09-24 19:07 UTCGHSA enrichment
  5. 2026-09-24 14:53 UTCEG score recompute
  6. 2026-09-24 14:53 UTCGHSA enrichment
  7. 2026-09-24 14:04 UTCEPSS rescore
  8. 2026-09-24 12:48 UTCGHSA enrichment
  9. 2026-09-24 08:34 UTCGHSA enrichment
  10. 2026-09-24 04:20 UTCGHSA enrichment
  11. 2026-09-24 00:05 UTCGHSA enrichment
  12. 2026-09-23 19:51 UTCEG score recompute
  13. 2026-09-23 19:51 UTCGHSA enrichment
  14. 2026-09-23 17:54 UTCEPSS rescore
  15. 2026-09-23 15:38 UTCEG score recompute
  16. 2026-09-23 15:38 UTCGHSA enrichment
  17. 2026-09-23 11:23 UTCGHSA enrichment
  18. 2026-09-23 11:06 UTCEG score recompute▲ 9.00
  19. 2026-09-23 11:06 UTCGHSA enrichment
  20. 2026-09-23 11:06 UTCMITRE cvelistV5CVSS v3 → 9 · severity → CRITICAL
  21. 2026-09-23 06:17 UTCNVD update
  22. 2026-09-23 06:06 UTCEG score recompute
  23. 2026-09-23 06:06 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-82843?
CVE-2026-82843 is a critical vulnerability published on September 23, 2026. The WP OAuth Server ( Login with WordPress ) WordPress plugin before 6.4.0 does not bind the OpenID Connect identity assertion it issues to the authorization grant being exchanged, returning instead the assertion belonging to whichever user authenticated most recently, which allows users with the…
When was CVE-2026-82843 disclosed?
CVE-2026-82843 was first published in the National Vulnerability Database on September 23, 2026, with the most recent update on September 24, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-82843 actively exploited?
CVE-2026-82843 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 92.7% of all scored CVEs.
What is the CVSS score of CVE-2026-82843?
CVE-2026-82843 has a CVSS v3.1 base score of 9.0 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-82843?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-82843, 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-2026-82843

Explore →

Is Your Infrastructure Affected by CVE-2026-82843?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Book a Demo →Browse All CVEs