PatchTheCVECVE-2026-73311: XenForo before 2.3.13 contains an OAuth2 authorization code reuse vulnerability that allows attackers to obtai
CVE-2026-73311 is a high-severity flaw (CVSS 7.4) affecting xenforo. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
XenForo before 2.3.13 contains an OAuth2 authorization code reuse vulnerability that allows attackers to obtain unauthorized token pairs by submitting a previously used authorization code. Attackers can exploit the failure to invalidate or mark authorization codes as consumed after initial token issuance to receive an independent token pair for the same user and scopes, bypassing the single-use guarantee of the OAuth2 authorization code flow.
Why this priority
- High severity
- Public exploit reference
- Remotely exploitable, no login, no user action
A fixed release or distro patch exists.
Risk facts
| CVSS score | 7.4 (High) |
| Attack vector | Network (remote) |
| Attack complexity | High |
| Privileges needed | None |
| User interaction | None |
| EPSS exploit chance | 0.5% (top 58%) |
| CISA exploited list | No |
| Weakness | CWE-294 |
| Published | 2026-09-08 |
| Last modified | 2026-09-11 |
Last updated 2026-09-11 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2026-73311?
xenforo: upgrade to 2.3.13. Exact commands for each OS are on this page.
Is CVE-2026-73311 being exploited?
CVE-2026-73311 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2026-73311 affect?
CVE-2026-73311 affects xenforo. Severity is high (CVSS 7.4). XenForo before 2.3.13 contains an OAuth2 authorization code reuse vulnerability that allows attackers to obtain unauthorized token pairs by submitting a previously used authorization code. Attackers can exploit the failure to invalidate or
How urgent is CVE-2026-73311?
Priority 47/100. High severity; Public exploit reference; Remotely exploitable, no login, no user action
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