CVE-2026-73320 XenForo < 2.3.13 Unauthenticated Information Disclosure via Unfurl Endpoint

What is CVE-2026-73320?

CVE-2026-73320 is a medium-severity vulnerability in XenForo, published on 8 Sep 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

Official description

XenForo before 2.3.13 contains an unauthenticated information disclosure vulnerability that allows unauthenticated attackers to retrieve private unfurl records by supplying predictable auto-increment primary key IDs to the unfurl endpoint. Attackers can enumerate or predict result IDs and query the endpoint without any session, user, or visibility checks to obtain rendered preview HTML, original URLs, and query strings from private conversations and other restricted content.

Weakness: CWE-639

Which versions are affected by CVE-2026-73320?

It affects 1 product.

Products include Xenforo Xenforo.

How do I fix CVE-2026-73320?

No fix has been published for CVE-2026-73320 yet. Limit exposure of the affected software until one is available.

Is CVE-2026-73320 being exploited?

There is no known exploitation of CVE-2026-73320 in the wild and no public exploit code.

Public exploit code: 1 proofs of concept on GitHub.

Other vulnerabilities in XenForo

• CVE-2025-71279 XenForo Passkey Security Bypass Critical 9.3
• CVE-2026-73309 XenForo < 2.3.13 Authentication Bypass via OAuth2 Token Endpoint Critical 9.1
• CVE-2026-73311 XenForo < 2.3.13 OAuth2 Authorization Code Reuse Critical 9.1
• CVE-2026-73312 XenForo < 2.3.13 Refresh Token Replay via Expired Access Token Critical 9.1
• CVE-2024-38457 Xenforo before 2.2.16 allows CSRF. High 8.8

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-5j56-975f-v5v8.