CVE-2026-73310 XenForo < 2.3.13 OAuth2 Authorization Code Token Theft via redirect_uri Bypass
Attackers can steal OAuth2 tokens by bypassing redirect URI validation, leading to account takeover and data access in XenForo.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-73310?
CVE-2026-73310 is a high-severity authentication bypass vulnerability in XenForo, published on 8 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
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.
Weakness: CWE-863
Which versions are affected by CVE-2026-73310?
It affects 1 product.
Products include Xenforo Xenforo.
How do I fix CVE-2026-73310?
No fix has been published for CVE-2026-73310 yet. Limit exposure of the affected software until one is available.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2026-73310 being exploited?
There is no known exploitation of CVE-2026-73310 in the wild and no public exploit code.
Public exploit code: 1 proofs of concept on GitHub.
Other vulnerabilities in XenForo
- CVE-2025-71279 XenForo Passkey Security Bypass
- CVE-2026-73309 XenForo < 2.3.13 Authentication Bypass via OAuth2 Token Endpoint
- CVE-2026-73311 XenForo < 2.3.13 OAuth2 Authorization Code Reuse
- CVE-2026-73312 XenForo < 2.3.13 Refresh Token Replay via Expired Access Token
- CVE-2024-38457 Xenforo before 2.2.16 allows CSRF.
Sources
Also known as GHSA-3hj9-69jw-9xx6.