PatchTheCVECVE-2026-73314: XenForo before 2.3.13 contains a signature verification logic error in the PayPal REST webhook handler that al
CVE-2026-73314 is a high-severity flaw (CVSS 7.5) 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 a signature verification logic error in the PayPal REST webhook handler that allows unauthenticated attackers to bypass payment signature validation by submitting a webhook request with an unsupported auth_algo header value. When the algorithm cannot be mapped to a supported hash function, the verification function incorrectly returns true instead of failing, causing the caller to treat the fabricated request as ver
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 | 7.5 (High) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | None |
| User interaction | None |
| EPSS exploit chance | 0.7% (top 49%) |
| CISA exploited list | No |
| Weakness | CWE-754 |
| 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-2026-73314?
xenforo: upgrade to 2.3.13. Exact commands for each OS are on this page.
Is CVE-2026-73314 being exploited?
CVE-2026-73314 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-2026-73314 affect?
CVE-2026-73314 affects xenforo. Severity is high (CVSS 7.5). XenForo before 2.3.13 contains a signature verification logic error in the PayPal REST webhook handler that allows unauthenticated attackers to bypass payment signature validation by submitting a webhook request with an unsupported auth_alg
How urgent is CVE-2026-73314?
Priority 49/100. High severity; Public exploit reference; Remotely exploitable, no login, no user action
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