CVE-2026-73315
XenForo < 2.3.13 SSRF via PayPal REST Webhook Handler
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.
INFO
Published Date :
Sept. 8, 2026, 2:17 p.m.
Last Modified :
Sept. 8, 2026, 2:17 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-73315
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | HIGH | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 3.1 | HIGH | [email protected] | ||||
| CVSS 4.0 | HIGH | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 4.0 | HIGH | [email protected] |
Solution
- Update XenForo to version 2.3.13.
- Apply vendor patches for the PayPal REST webhook handler.
- Validate certificate URLs for scheme and hostname.
- Implement allowlist validation for webhook headers.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-73315.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-73315 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-73315
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-73315 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-73315 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by [email protected]
Sep. 08, 2026
Action Type Old Value New Value Added 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. Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N Added CWE CWE-918 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/73xxx/CVE-2026-73315.json">CVE-2026-73315</a> Added Reference https://www.vulncheck.com/advisories/xenforo-ssrf-via-paypal-rest-webhook-handler Added Reference https://xenforo.com/community/threads/security-fixes-released-for-all-xenforo-and-media-gallery-versions-2-2-0-2-3-12.239856/ Added Reference https://xenforo.com/community/threads/xenforo-2-3-13-and-add-ons-released-includes-security-fixes.239857/ -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Sep. 08, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-73315', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'yes'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-09-08T13:42:15.724503Z'}