CVE-2026-53961
Discourse: Forged AWS SNS bounce notifications can disable a targeted user's email (missing TopicArn binding)
- State
- Published
- Severity
- 6.5 Medium
- Published
- Jul 9, 2026
- Updated
- Jul 10, 2026
- Reserved
- Jun 11, 2026
Description
Discourse is an open-source discussion platform. Prior to 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5, the AWS SES bounce webhook at POST /webhooks/aws verified that SNS messages were signed by Amazon but did not bind them to trusted TopicArn values, allowing any AWS account holder to publish validly signed forged Bounce notifications that revoke a targeted user email. This issue is fixed in versions 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 6.5 Medium | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L | GitHub_M |
Weaknesses
- CWE-345 Insufficient Verification of Data Authenticity
Affected Products
| Product | Versions |
|---|---|
discoursediscourse |
|
References
- https://github.com/discourse/discourse/security/advisories/GHSA-8f9m-v436-wr3x
- https://github.com/discourse/discourse/commit/3a3d315a85ef3c6aabfc7e7bb38702059784f06b
- https://github.com/discourse/discourse/commit/61f12e13aa1b760f81d5ff60f12e3a7e77434b94
- https://github.com/discourse/discourse/commit/958f0cd831d65a49ec75f05343ca2c167679f0ea
- https://github.com/discourse/discourse/commit/aea35190791261bab258ebab05da279e78cdd0e6
- https://github.com/discourse/discourse/releases/tag/v2026.1.5
- https://github.com/discourse/discourse/releases/tag/v2026.4.2
- https://github.com/discourse/discourse/releases/tag/v2026.5.1
- https://github.com/discourse/discourse/releases/tag/v2026.6.0
Every record here comes from the CVE Program’s CVE List. © 1999–2026 The MITRE Corporation. CVE is a registered trademark of The MITRE Corporation. The records are reproduced under the CVE Program terms of use.