CVE-2026-73312
XenForo < 2.3.13 Refresh Token Replay via Expired Access Token
CRITICAL 9.1EPSS 0.5%
XenForo before 2.3.13 contains a refresh token replay vulnerability that allows attackers to reuse a refresh token multiple times by exploiting the failure to mark tokens as consumed when the parent access token has expired. Attackers can repeatedly submit the same refresh token to generate additional independent token pairs, achieving persistent unauthorized access for the token's full lifetime.
- Affected
- XenForo
- CVSS v4.0 VULNCHECK
- 9.1 CRITICAL
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/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/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS v3.1 VULNCHECK
- 7.4 HIGH
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N - EPSS
- 0.47% chance of exploitation in the next 30 days, 40th percentile
- Published
- 2026-09-08
- Updated
- 2026-10-01
Proof-of-concept exploits (1)
- BomboBombone/CVE-2026-733120★ · 2026-09-08
Security advisories
- https://bombobombone.github.io/posts/cve-2026-73312
- https://www.vulncheck.com/advisories/xenforo-refresh-token-replay-via-expired-access-token
- https://xenforo.com/community/threads/security-fixes-released-for-all-xenforo-and-media-g…
- https://xenforo.com/community/threads/xenforo-2-3-13-and-add-ons-released-includes-securi…