CVE Catalog

CVE-2026-73314

HighCVSS 7.5
Published: Translated: NVD NIST

Summary

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.

Risk Assessment

An attacker can forge webhook requests and process payment events without a valid PayPal signature, potentially leading to unauthorized account or subscription activations.

Recommendation

It is recommended to update XenForo to version 2.3.13 or later, which includes a fix for this logic error.

Other vulnerabilities in XenForo

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Original NVD description (English source)

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 verified and process the payment event without a valid PayPal signature.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS