CVE-2025-71278 XenForo OAuth2 Unauthorized Scope Request
OAuth2 clients can request unauthorized scopes, potentially gaining access beyond intended authorization levels in XenForo installations using OAuth2.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2025-71278?
CVE-2025-71278 is a high-severity authentication bypass vulnerability in XenForo, published on 1 Apr 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
XenForo before 2.3.5 allows OAuth2 client applications to request unauthorized scopes. This affects any customer using OAuth2 clients on any version of XenForo 2.3 prior to 2.3.5, potentially allowing client applications to gain access beyond their intended authorization level.
Weakness: CWE-863
Which versions are affected by CVE-2025-71278?
It affects 1 product.
Products include Xenforo Xenforo.
How do I fix CVE-2025-71278?
No fix has been published for CVE-2025-71278 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-2025-71278 being exploited?
There is no known exploitation of CVE-2025-71278 in the wild and no public exploit code.
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-499p-g3jm-62mp.