CVE-2026-73315Network attack vector

Unauthenticated SSRF via unvalidated webhook certificate URL

Published Sep 8, 2026 · Updated Sep 9, 2026

Server-side request forgery in XenForo before 2.3.13 allows remote attackers to read internal resources through a PayPal REST webhook. The handler fetches a certificate URL supplied in webhook headers without validating its scheme, hostname, or membership in an allowlist. No authentication is required; reachable consequences include cloud instance metadata and IAM credential disclosure or secondary internal-service exploitation.

CVSS severity7.7
High
EPSS probability0.27%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Server-side request forgery in XenForo before 2.3.13 allows remote attackers to read internal resources through a PayPal REST webhook. The handler fetches a certificate URL supplied in webhook headers without validating its scheme, hostname, or membership in an allowlist. No authentication is required; reachable consequences include cloud instance metadata and IAM credential disclosure or secondary internal-service exploitation.

The record

CVE
CVE-2026-73315
Published
Sep 8, 2026
Updated
Sep 9, 2026
Vendor
XenForo Ltd.
Product
XenForo
Classifications
CWE-918, CAPEC-664, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 8, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 9, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <2.3.13

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

XenForo Ltd. · XenForoversion=0 <2.3.13

Published CVSS scores

8.6VulnCheckCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N
7.7VulnCheckCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-918Server-Side Request Forgery (SSRF)
CAPEC-664Server Side Request Forgery
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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