CVE-2026-73310

XenForo < 2.3.13 OAuth2 Authorization Code Token Theft via redirect_uri Bypass

8.2 HighPublic exploit

XenForo before 2.3.13 contains an authorization flaw in the OAuth2 token endpoint that allows attackers controlling any allowlisted redirect URI to bypass redirect URI binding by submitting a different allowlisted URI than the one recorded at authorization time. Attackers can exchange an intercepted authorization code using a mismatched redirect URI to steal OAuth2 tokens from intercepted authorization flows.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: High
Privileges needed: None
User interaction: None

What an attacker can affect

Confidentiality: High
Integrity: None
Availability: None

Exploit likelihood

0.48%Up 0.1 points since Sep 9, 2026

What each source reports

CVE List Score used 8.2

XenForo < 2.3.13 OAuth2 Authorization Code Token Theft via redirect_uri Bypass

Record: CVE-2026-73310
CVSS 4.0: 8.2 HighCVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
CVSS 3.1: 5.9 MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
Weakness: CWE-863
Updated: 2026-11-02

EUVDEUVD-2026-72781 8.2

Record: EUVD-2026-72781
CVSS 4.0: 8.2 HighCVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
Updated: 2026-11-02

GitHub AdvisoriesGHSA-3hj9-69jw-9xx6 8.2

XenForo before 2.3.13 contains an authorization flaw in the OAuth2 token endpoint that allows...

Record: GHSA-3hj9-69jw-9xx6
CVSS 4.0: 8.2 HighCVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/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
CVSS 3.1: 5.9 MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
Weakness: CWE-863
Updated: 2026-11-02

NVD 8.2

Record: CVE-2026-73310
CVSS 4.0: 8.2 HighCVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/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
CVSS 3.1: 5.9 MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
CVSS 3.1: 5.9 MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
Weakness: CWE-863
Updated: 2026-11-02

Affected products

xenforo

Public exploits

Links only. Every CVE stores no exploit code.

Public exploits
Source	Link	Date
PoC in GitHub	BomboBombone/CVE-2026-73310	2026-09-08

History

History
Recorded	Changed	Sources
Nov 2, 2026	first indexed	CVE List, EUVD, GitHub Advisories, NVD, PoC in GitHub

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2026-73310 is a high vulnerability (CVSS 8.2) in Xenforo, published September 8, 2026. Public exploit code exists. EPSS puts the chance of exploitation in the next 30 days at 0.48%, the 42nd percentile. No source names a fixed version.