CVE-2026-53961

Summary

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.

Affected Software

VendorProductVersion RangeStatus
discoursediscourse>= 2026.5.0-latest, < 2026.5.1affected
discoursediscourse>= 2026.4.0-latest, < 2026.4.2affected
discoursediscourse>= 2026.1.0-latest, < 2026.1.5affected

Weaknesses

  • CWE-345: CWE-345: Insufficient Verification of Data Authenticity

References