What is CVE-2023-32682?

CVE-2023-32682 is a medium-severity vulnerability in Matrix Synapse, classified under Improper Authentication. CVSS score: 5.4/10. Published 2023-06-06.

How severe is CVE-2023-32682?

Medium severity. CVSS v3 base score is 5.4 out of 10.

Auth bypass in Matrix Synapse

CVE-2023-32682

Synapse is a Matrix protocol homeserver written in Python with the Twisted framework. In affected versions it may be possible for a deactivated user to login when using uncommon configurations. This only applies if any of the following are true: 1. JSON Web Tokens are enabled for login via the `jwt_config.enabled` configuration setting. 2. The local password database is enabled via the `password_config.enabled` and `password_config.localdb_enabled` configuration settings *and* a user's password is updated via an admin API after a user is deactivated. Note that the local password database is enabled by default, but it is uncommon to set a user's password after they've been deactivated. Installations that are configured to only allow login via Single Sign-On (SSO) via CAS, SAML or OpenID Connect (OIDC); or via an external password provider (e.g. LDAP) are not affected. If not using JSON Web Tokens, ensure that deactivated users do not have a password set. This issue has been addressed in version 1.85.0. Users are advised to upgrade.

Vulnerability class: Broken Authentication

Published 2023-06-06 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.008 (53.2th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 53rd percentile — 53.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.008 · newest: 0.008 · change: 0.000

Affected products

Matrix Synapse
Matrix-Org Synapse — versions < 1.85.0

Weakness classification (CWE)

CWE-287 — Improper Authentication

References

github.com/matrix-org/synapse/security/advisories/GHSA-26c5-ppr8-f33p (Patch, Mitigation, Vendor Advisory)
github.com/matrix-org/synapse/pull/15624 (Patch)
github.com/matrix-org/synapse/pull/15634 (Patch)
matrix-org.github.io/synapse/latest/admin_api/user_admin_api.html (Product)
matrix-org.github.io/synapse/latest/jwt.html (Product)
matrix-org.github.io/synapse/latest/usage/configuration/config_documentation.ht… (Product)
lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/…

Frequently asked questions

What is CVE-2023-32682?: CVE-2023-32682 is a medium-severity vulnerability in Matrix Synapse, classified under Improper Authentication. CVSS score: 5.4/10. Published 2023-06-06.
How severe is CVE-2023-32682?: Medium severity. CVSS v3 base score is 5.4 out of 10.