Quick answers
- Is CVE-2026-84203 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-84203 being exploited in the wild.
- How severe is CVE-2026-84203?
- High severity, with a CVSS score of 8.1, published 1 September 2026.
- Which products and versions are affected?
- Memos Memos 0.26.0 through 0.30.0.
- Is there a fix for CVE-2026-84203?
- No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
- How is CVE-2026-84203 attacked?
- It is attacked over the network, in a web application.
- Am I affected by CVE-2026-84203?
- Check whether anything you run is named in the advisory. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
This is an authentication bypass vulnerability in Memos versions 0.26.0 through 0.30.0 stemming from incomplete token revocation logic in the password change function. The vulnerable component is the authentication handler in server/auth/authenticator.go, which does not revoke existing refresh tokens when a password change occurs. An attacker who has previously obtained a refresh token (e.g., through theft or phishing) can call the RefreshToken RPC endpoint to obtain new access tokens and rotate the refresh token indefinitely, completely circumventing the intended security benefit of a password change. This attack requires only network access to the Memos API and a valid refresh token; no authentication or user interaction is needed beyond possession of the token. The vulnerability allows persistent account compromise even after a victim changes their password.
Affected products
- Memos Memos 0.26.0 through 0.30.0
Timeline
- 2026-09-01: disclosed