CVE-2023-28107: Discourse vulnerable to multisite DoS by spamming backups

Severity: medium (CVSS 4.9 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.7% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2023-03-17 · updated 2026-06-17
Weakness: CWE-770

Description

Discourse is an open-source discussion platform. Prior to version 3.0.2 of the `stable` branch and version 3.1.0.beta3 of the `beta` and `tests-passed` branches, a user logged as an administrator can request backups multiple times, which will eat up all the connections to the DB. If this is done on a site using multisite, then it can affect the whole cluster. The vulnerability is patched in version 3.0.2 of the `stable` branch and version 3.1.0.beta3 of the `beta` and `tests-passed` branches. There are no known workarounds.

Affected products

discourse: through 3.0.1; before 3.1.0; 3.1.0-beta1, 3.1.0-beta2 — fixed in 3.1.0

How to fix

Upgrade to a fixed version: discourse 3.1.0. Check the vendor advisory for mitigations.

References

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