SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityAnalyzed

CVE-2026-53961

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…

MEDIUM 6.5EPSS 0.30%

Does this matter?

Lower severity and a low EPSS score (0.30%). Track it; it rarely justifies an emergency change on its own.

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.

CVSS 3.1
6.5 MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L
EPSS
0.30% probability · 23th percentile
CISA KEV
Not listed
Weakness
CWE-345
Affected
discourse/discourse
Source
security-advisories@github.com

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.