CVE-2026-53961
MEDIUM
6.5
CVSS 3.1
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.
Metadata
Severity & Metrics
6.5
MEDIUM CVSS 3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L
Affected products (1)
| Vendor | Product | Platform | Versions |
|---|---|---|---|
| discourse | discourse | — | >= 2026.5.0-latest, < 2026.5.1, >= 2026.4.0-latest, < 2026.4.2, >= 2026.1.0-latest, < 2026.1.5 |
Weakness (CWE)
| CWE | Source | Description |
|---|---|---|
| CWE-345 | cna | CWE-345: Insufficient Verification of Data Authenticity |
CVSS scores (1)
| Score | Severity | Version | Source | Vector |
|---|---|---|---|---|
| 6.5 | MEDIUM | 3.1 | cna | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L |
References (9)
- https://github.com/discourse/discourse/security/advisories/GHSA-8f9m-v436-wr3x https://github.com/discourse/discourse/security/advisories/GHSA-8f9m-v436-wr3x
- https://github.com/discourse/discourse/commit/3a3d315a85ef3c6aabfc7e7bb38702059784f06b https://github.com/discourse/discourse/commit/3a3d315a85ef3c6aabfc7e7bb38702059784f06b
- https://github.com/discourse/discourse/commit/61f12e13aa1b760f81d5ff60f12e3a7e77434b94 https://github.com/discourse/discourse/commit/61f12e13aa1b760f81d5ff60f12e3a7e77434b94
- https://github.com/discourse/discourse/commit/958f0cd831d65a49ec75f05343ca2c167679f0ea https://github.com/discourse/discourse/commit/958f0cd831d65a49ec75f05343ca2c167679f0ea
- https://github.com/discourse/discourse/commit/aea35190791261bab258ebab05da279e78cdd0e6 https://github.com/discourse/discourse/commit/aea35190791261bab258ebab05da279e78cdd0e6
- https://github.com/discourse/discourse/releases/tag/v2026.1.5 https://github.com/discourse/discourse/releases/tag/v2026.1.5
- https://github.com/discourse/discourse/releases/tag/v2026.4.2 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/v2026.5.1
- https://github.com/discourse/discourse/releases/tag/v2026.6.0 https://github.com/discourse/discourse/releases/tag/v2026.6.0