CVE•Published 2026-09-08•Modified 2026-09-11•0 articles on news•6 live references•NVD data

CVE-2026-73311Xenforo · Xenforo

Vulnerability data via NVD (ingested)

CVSS v3.1

7.4

HIGH

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

EPSS percentile

Exploit Prediction Scoring System · top 70% of all CVEs

Weaknesses (CWE)

CWE-294Authentication Bypass by Capture-replay

Description

XenForo before 2.3.13 contains an OAuth2 authorization code reuse vulnerability that allows attackers to obtain unauthorized token pairs by submitting a previously used authorization code. Attackers can exploit the failure to invalidate or mark authorization codes as consumed after initial token issuance to receive an independent token pair for the same user and scopes, bypassing the single-use guarantee of the OAuth2 authorization code flow.

Timeline

Published 2026-09-08

Modified 2026-09-11

External references

NVD MITRE Exploit-DB GitHub PoC 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-2026-73311

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-2026-73311