6.5 MEDIUM
- CVSS version (CVSS): 3.1
- Attack Vector (AV): Network (N)
- Attack Complexity (AC): Low (L)
- Privileges Required (PR): None (N)
- User Interaction (UI): None (N)
- Scope (S): Unchanged (U)
- Confidentiality (C): None (N)
- Integrity (I): Low (L)
- Availability (A): Low (L)
- Modified Attack Vector (MAV): Network (N)
- Modified Attack Complexity (MAC): Low (L)
- Modified Privileges Required (MPR): None (N)
- Modified User Interaction (MUI): None (N)
- Modified Confidentiality (MC): None (N)
- Modified Scope (MS): Unchanged (U)
- Modified Integrity (MI): Low (L)
- Modified Availability (MA): Low (L)
Activity log
- Created suggestion
Discourse: Forged AWS SNS bounce notifications can disable a targeted user's email (missing TopicArn binding)
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.
References
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https://github.com/discourse/discourse/security/advisories/GHSA-8f9m-v436-wr3x x_refsource_CONFIRM
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https://github.com/discourse/discourse/releases/tag/v2026.1.5 x_refsource_MISC
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https://github.com/discourse/discourse/releases/tag/v2026.4.2 x_refsource_MISC
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https://github.com/discourse/discourse/releases/tag/v2026.5.1 x_refsource_MISC
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https://github.com/discourse/discourse/releases/tag/v2026.6.0 x_refsource_MISC
Affected products
- ==>= 2026.5.0-latest, < 2026.5.1
- ==>= 2026.4.0-latest, < 2026.4.2
- ==>= 2026.1.0-latest, < 2026.1.5
Matching in nixpkgs
pkgs.discourse
Open source discussion platform
pkgs.discourseAllPlugins
Open source discussion platform
pkgs.discourse-mail-receiver
Helper program which receives incoming mail for Discourse
pkgs.python313Packages.pydiscourse
Python library for working with Discourse
pkgs.python314Packages.pydiscourse
Python library for working with Discourse
pkgs.grafanaPlugins.grafana-discourse-datasource
Allows users to search and view topics, posts, users, tags, categories, and reports on a given Discourse forum through Grafana
Package maintainers
-
@talyz Kim Lindberger <kim.lindberger@gmail.com>
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@leona-ya Leona Maroni <nix@leona.is>
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@nagisa Simonas Kazlauskas <nixpkgs@kazlauskas.me>
-
@Dettorer Paul Hervot <paul.hervot@dettorer.net>