CVE-2026-73311

HIGHPre-NVD 7.47.4—
EchelonGraph scoreHIGH confidence

Score 7.4 from GitHub Security Advisory (severity: CRITICAL) published 2026-09-08. a secondary CVSS source baseline 7.4; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 3 sources updated this weekElevated
7.4EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.4Exploit: Elevated riskExposed: 0

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

XenForo before 2.3.13 contains an OAuth2 authorization code reuse vulnerability that allows attackers to obtain unauthorized token pairs by submitting a previously used authorization code. Attackers can exploit the failure to invalidate or mark authorization codes as consumed after initial token issuance to receive an independent token pair for the same user and scopes, bypassing the single-use guarantee of the OAuth2 authorization code flow.

CVSS v3
7.4
EG Score
7.4(high)
EG Risk
49(Track*)
EG Risk 49/100SSVC: 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
Severity74% × 45%
Exploitation40% × 40%
Automatability0% × 15%
Action: Watch closely — could escalate to Attend.
EPSS PROB
0%
EPSS %ILE
31%
KEV
Not listed

Published

September 8, 2026

Last Modified

September 11, 2026

Advisory Details (1)

Auto-updated Sep 8, 2026
No patch confirmed yet.
generic

XenForo < 2.3.13 OAuth2 Authorization Code Reuse | Advisories | VulnCheck

https://www.vulncheck.com/advisories/xenforo-oauth2-authorization-code-reuse

Vendor Advisories for CVE-2026-73311(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 26× 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 13:26 UTCGHSA enrichment
  2. 2026-09-19 01:08 UTCEG score recompute
  3. 2026-09-19 01:08 UTCGHSA enrichment
  4. 2026-09-18 19:28 UTCEPSS rescore
  5. 2026-09-18 12:51 UTCGHSA enrichment
  6. 2026-09-18 00:33 UTCEG score recompute
  7. 2026-09-18 00:33 UTCGHSA enrichment
  8. 2026-09-17 12:15 UTCGHSA enrichment
  9. 2026-09-16 23:57 UTCEG score recompute
  10. 2026-09-16 23:57 UTCGHSA enrichment
  11. 2026-09-16 14:08 UTCEPSS rescore
  12. 2026-09-16 11:38 UTCEG score recompute
  13. 2026-09-16 11:38 UTCGHSA enrichment
  14. 2026-09-16 05:15 UTCEPSS rescore
  15. 2026-09-15 23:19 UTCGHSA enrichment
  16. 2026-09-15 10:58 UTCEG score recompute
  17. 2026-09-15 10:58 UTCGHSA enrichment
  18. 2026-09-15 03:12 UTCEPSS rescore
  19. 2026-09-14 22:34 UTCGHSA enrichment
  20. 2026-09-14 10:16 UTCGHSA enrichment
  21. 2026-09-13 21:59 UTCEG score recompute
  22. 2026-09-13 21:59 UTCGHSA enrichment
  23. 2026-09-13 09:41 UTCGHSA enrichment
  24. 2026-09-12 21:23 UTCEG score recompute
  25. 2026-09-12 21:23 UTCGHSA enrichment
Show 24 more
  1. 2026-09-12 15:02 UTCEPSS rescore
  2. 2026-09-12 09:05 UTCGHSA enrichment
  3. 2026-09-11 20:47 UTCGHSA enrichment
  4. 2026-09-11 17:24 UTCEG score recompute
  5. 2026-09-11 17:24 UTCGHSA enrichment
  6. 2026-09-11 14:53 UTCEPSS rescore
  7. 2026-09-11 04:42 UTCGHSA enrichment
  8. 2026-09-10 16:24 UTCEG score recompute
  9. 2026-09-10 16:24 UTCGHSA enrichment
  10. 2026-09-10 15:27 UTCEG score recompute
  11. 2026-09-10 15:27 UTCGHSA enrichment
  12. 2026-09-10 14:22 UTCEG score recompute
  13. 2026-09-10 14:22 UTCGHSA enrichment
  14. 2026-09-10 09:35 UTCEPSS rescore
  15. 2026-09-10 02:01 UTCGHSA enrichment
  16. 2026-09-09 13:43 UTCEG score recompute
  17. 2026-09-09 13:43 UTCGHSA enrichment
  18. 2026-09-09 01:18 UTCEG score recompute
  19. 2026-09-09 01:18 UTCGHSA enrichment
  20. 2026-09-08 20:12 UTCEG score recompute
  21. 2026-09-08 20:12 UTCGHSA enrichment
  22. 2026-09-08 14:30 UTCEG score recompute
  23. 2026-09-08 13:26 UTCEG score recompute
  24. 2026-09-08 13:24 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-73311?
CVE-2026-73311 is a high vulnerability published on September 8, 2026. XenForo before 2.3.13 contains an OAuth2 authorization code reuse vulnerability that allows attackers to obtain unauthorized token pairs by submitting a previously used authorization code. Attackers can exploit the failure to invalidate or mark authorization codes as consumed after initial token…
When was CVE-2026-73311 disclosed?
CVE-2026-73311 was first published in the National Vulnerability Database on September 8, 2026, with the most recent update on September 11, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-73311 actively exploited?
CVE-2026-73311 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 69.1% of all scored CVEs.
What is the CVSS score of CVE-2026-73311?
CVE-2026-73311 has a CVSS v3 base score of 7.4 (NVD).
How do I remediate CVE-2026-73311?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-73311, 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-2026-73311

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