CVE•Published 2026-09-08•Modified 2026-09-11•1 article on news•6 live references•NVD data

CVE-2026-73315Xenforo · Xenforo

Vulnerability data via NVD (ingested)

CVSS v3.1

8.6

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N

EPSS percentile

Exploit Prediction Scoring System · top 81% of all CVEs

Weaknesses (CWE)

CWE-918Server-Side Request Forgery (SSRF)

Description

XenForo before 2.3.13 contains a server-side request forgery vulnerability in the PayPal REST webhook handler that allows unauthenticated attackers to cause the server to make outbound HTTP requests to arbitrary destinations by supplying a crafted certificate URL in webhook headers without scheme, hostname, or allowlist validation. Attackers can submit a crafted POST to the PayPal webhook callback endpoint to reach internal network resources including cloud instance metadata services, potentially disclosing IAM credentials or enabling secondary internal service exploitation.

Timeline

Published 2026-09-08

Modified 2026-09-11

External references

NVD MITRE Exploit-DB Sploitus trickest/cve VulnCheck

Search for exposed instances

Shodan + Censys queries derived from NVD's CPE data. The vuln tag catches assets Shodan has explicitly linked to this CVE; the product / banner fingerprints find exposed instances even when the vuln tag was never applied (which is common).

Shodan · vuln tag0 hosts

vuln:CVE-2026-73315

Hosts Shodan has explicitly fingerprinted as vulnerable.

Shodan · product

product:"Xenforo Xenforo"

All exposed Xenforo Xenforo instances — cross-reference with the CVE's affected-version range.

Shodan · banner/body mention

http.html:"Xenforo"

HTTP body or banner mentions "Xenforo" — catches deploys Shodan didn't identify as a product.

More intel sources (5)

Shodan report

vuln:CVE-2026-73315