Vulnerability in Xenforo
CVE-2026-73312
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.4 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N.
EPSS exploit prediction
EPSS: 0.005 (40.1th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 40th percentile — 40.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: 0.000
Affected products
Weakness classification (CWE)
Public proof-of-concept exploits
References
- Vendor Advisory (vendor-advisory, patch, Release Notes)
- Release Notes (release-notes, Release Notes)
- www.vulncheck.com/advisories/xenforo-refresh-token-replay-via-expired-access-to… (Third Party Advisory, third-party-advisory)
- Researcher Advisory (Exploit, technical-description, Third Party Advisory)
- Researcher PoC (Exploit, exploit, Third Party Advisory)
Frequently asked questions
- What is CVE-2026-73312?
- CVE-2026-73312 is a high-severity vulnerability in Xenforo, classified under Authentication Bypass by Capture-replay. CVSS score: 7.4/10. Published 2026-09-08.
- How severe is CVE-2026-73312?
- High severity. CVSS v3 base score is 7.4 out of 10.
- Is CVE-2026-73312 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.