XenForo < 2.3.13 OAuth2 Authorization Code Token Theft via redirect_uri Bypass
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- High
- Attack requirements
- None
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- High · None · None
- Fix status
- Fixed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-863.
Summary
XenForo before 2.3.13 contains an authorization flaw in the OAuth2 token endpoint that allows attackers controlling any allowlisted redirect URI to bypass redirect URI binding by submitting a different allowlisted URI than the one recorded at authorization time. Attackers can exchange an intercepted authorization code using a mismatched redirect URI to steal OAuth2 tokens from intercepted authorization flows.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
- Fix · CNA XenForo (XenForo) Fixed in 2.3.13
Fixed in the same release
Records fixed by the same vendor advisory or release, as the CNA lists them.
- Advisory ·
XenForo — xenforo.com/community/threads/security-fixes-released-for-a…
14 records Highest priority Priority HIGH 4 HIGH, 5 MEDIUM, 5 LOW
Other records, highest priority first
- TI-2026-51441 XenForo < 2.3.13 Payment Replay via PayPal REST Payment ProviderPriority HIGH 77
- TI-2026-51439 XenForo < 2.3.13 Signature Verification Bypass via PayPal REST WebhookPriority HIGH 77
- TI-2026-51436 XenForo < 2.3.13 OAuth2 Authorization Code ReusePriority HIGH 74
Timeline
- 2026-10-02 Threatist record created from CVE-2026-73310
- 2026-10-03 Alias added: GHSA-3hj9-69jw-9xx6
References
More Xenforo vulnerabilities
- TI-2026-51441 XenForo < 2.3.13 Payment Replay via PayPal REST Payment Provider CVSS 4.0HIGH 8.7
- TI-2026-51439 XenForo < 2.3.13 Signature Verification Bypass via PayPal REST Webhook CVSS 4.0HIGH 8.7
- TI-2026-51436 XenForo < 2.3.13 OAuth2 Authorization Code Reuse CVSS 4.0CRITICAL 9.1
- TI-2026-51434 XenForo < 2.3.13 Authentication Bypass via OAuth2 Token Endpoint CVSS 4.0CRITICAL 9.1
- TI-2024-25701 Xenforo before 2.2.16 allows code injection. CVSS 3.1HIGH 8.8
- TI-2026-51446 XenForo < 2.3.13 Uncontrolled Recursion DoS via BBCode Parser CVSS 4.0HIGH 7.1
Sources
- CVE-2026-73310 · CVE Program
- CVE-2026-73310 · NVD
- FIRST EPSS
- GHSA-3hj9-69jw-9xx6 · GitHub Advisory Database · CC BY 4.0
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