CVE-2026-73315: XenForo before 2.3.13 contains a server-side request forgery vulnerability in the PayPal REST webhook handler

Q: How do I fix CVE-2026-73315?

xenforo: upgrade to 2.3.13. Exact commands for each OS are on this page.

Q: Is CVE-2026-73315 being exploited?

CVE-2026-73315 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-73315 affect?

CVE-2026-73315 affects xenforo. Severity is high (CVSS 8.6). 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

Q: How urgent is CVE-2026-73315?

Priority 47/100. High severity; Public exploit reference; Remotely exploitable, no login, no user action

This week

HIGH 8.6REMOTEUPGRADE

CVE-2026-73315 is a high-severity flaw (CVSS 8.6) affecting xenforo. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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 incl

Why this priority

High severity
Public exploit reference
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	8.6 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.4% (top 71%)
CISA exploited list	No
Weakness	CWE-918
Published	2026-09-08
Last modified	2026-09-11

Publisher (CNA): VulnCheck · Vendor: xenforo

Last updated 2026-09-11 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-09-08 14:17 UTCPublished CVE record published
2026-09-11 20:31 UTCUpdated Record last modified

xenforo xenforo UPGRADE

Affected: < 2.3.13

Fixed in: 2.3.13

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy xenforo || rpm -q xenforo || xenforo --version

2. UPGRADE to 2.3.13 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade xenforo

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade xenforo

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-73315?

xenforo: upgrade to 2.3.13. Exact commands for each OS are on this page.

Is CVE-2026-73315 being exploited?

CVE-2026-73315 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-73315 affect?

CVE-2026-73315 affects xenforo. Severity is high (CVSS 8.6). 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

How urgent is CVE-2026-73315?

Priority 47/100. High severity; Public exploit reference; Remotely exploitable, no login, no user action

Related CVEs

CVE-2026-73318 LOW 3.8 UPGRADE XenForo before 2.3.13 contains a missing authorization vulnerability in the force-agreement controller that al
CVE-2026-73313 MEDIUM 6.8 UPGRADE XenForo before 2.3.13 contains a multi-factor authentication bypass vulnerability in the passkey TFA provider
CVE-2026-73310 MEDIUM 5.9 UPGRADE XenForo before 2.3.13 contains an authorization flaw in the OAuth2 token endpoint that allows attackers contro
CVE-2026-73309 HIGH 7.4 UPGRADE XenForo before 2.3.13 contains an authentication bypass vulnerability in the OAuth2 token endpoint that allows
CVE-2026-73316 HIGH 7.5 UPGRADE XenForo before 2.3.13 contains a payment replay vulnerability in the PayPal REST payment provider that allows

References

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