VulnerabilityAnalyzed

CVE-2025-71278

XenForo before 2.3.5 allows OAuth2 client applications to request unauthorized scopes.

HIGH 8.7EPSS 0.27%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.27%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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.

CVSS 4.0: 8.7 HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
EPSS: 0.27% probability · 18th percentile
Public exploits: None in Exploit-DB
CISA KEV: Not listed
Weakness: CWE-863
Affected: xenforo/xenforo
Source: disclosure@vulncheck.com

EPSS trend

EPSS 0.3% since 27 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

References

https://www.vulncheck.com/advisories/xenforo-oauth2-unauthorized-scope-requestThird Party Advisory
https://xenforo.com/community/threads/xenforo-2-3-5-includes-security-fix-add-ons-released.228812/Release Notes

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.