What’s Vulnerable › Vulnerabilities

CVE-2021-37693: Re-use of email tokens in Discourse

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.8% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2021-08-13 · updated 2026-06-17
• Weakness: CWE-613

Description

Discourse is an open-source platform for community discussion. In Discourse before versions 2.7.8 and 2.8.0.beta4, when adding additional email addresses to an existing account on a Discourse site an email token is generated as part of the email verification process. Deleting the additional email address does not invalidate an unused token which can then be used in other contexts, including reseting a password.

Affected products

• discourse: before 2.7.8; 2.8.0-beta1, 2.8.0-beta2, 2.8.0-beta3 — fixed in 2.7.8

How to fix

Upgrade to a fixed version: discourse 2.7.8. Check the vendor advisory for mitigations.

References

• https://github.com/discourse/discourse/commit/fb14e50741a4880cda22244eded8858e2f5336ef
• https://github.com/discourse/discourse/security/advisories/GHSA-9377-96f4-cww4
• https://github.com/discourse/discourse/commit/fb14e50741a4880cda22244eded8858e2f5336ef
• https://github.com/discourse/discourse/security/advisories/GHSA-9377-96f4-cww4

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