CVE-2026-53961

Severity CVSS v4.0:

Pending analysis

Type:

CWE-345 Insufficient Verification of Data Authenticity

Publication date:

09/07/2026

Last modified:

14/07/2026

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.

Impact

Vector 3.x

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L CVSS v3.1 Severity and Metrics:

Base Score: 6.50 MEDIUM
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L

Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): None
Scope (S): Unchanged
Confidentiality (C): None
Integrity (I): Low
Availability (A): Low

Base Score 3.x

6.50

Severity 3.x

MEDIUM

Vulnerable products and versions

CPE	From	Up to
cpe:2.3:a:discourse:discourse::::::::	2026.1.0 (including)	2026.1.5 (excluding)
cpe:2.3:a:discourse:discourse::::::::	2026.4.0 (including)	2026.4.2 (excluding)
cpe:2.3:a:discourse:discourse::::::::	2026.5.0 (including)	2026.5.1 (excluding)
cpe:2.3:a:discourse:discourse:2026.6.0::::latest:::

To consult the complete list of CPE names with products and versions, see this page

CVE-2026-53961

Description

Impact

Vulnerable products and versions

References to Advisories, Solutions, and Tools