Discourse up to 2026.1.4/2026.4.1/2026.5.0 AWS SES Bounce Webhook /webhooks/aws input validation

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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7.0$0-$5k1.12

Summaryinfo

A vulnerability classified as critical has been found in Discourse up to 2026.1.4/2026.4.1/2026.5.0. This affects an unknown function of the file /webhooks/aws of the component AWS SES Bounce Webhook. This manipulation causes input validation. This vulnerability is handled as CVE-2026-53961. The attack can be initiated remotely. There is not any exploit available.

Detailsinfo

A vulnerability was found in Discourse up to 2026.1.4/2026.4.1/2026.5.0. It has been declared as critical. Affected by this vulnerability is some unknown processing of the file /webhooks/aws of the component AWS SES Bounce Webhook. The manipulation with an unknown input leads to a input validation vulnerability. The CWE definition for the vulnerability is CWE-20. The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

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.

The advisory is shared at github.com. This vulnerability is known as CVE-2026-53961 since 06/11/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Technical details are known, but no exploit is available.

Upgrading to version 2026.6.0, 2026.5.1, 2026.4.2 or 2026.1.5 eliminates this vulnerability.

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Type

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.3
VulDB Meta Temp Score: 7.0

VulDB Base Score: 7.3
VulDB Temp Score: 7.0
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
💳💳💳💳💳💳
💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Input validation
CWE: CWE-20
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔒

Upgrade: Discourse 2026.6.0/2026.5.1/2026.4.2/2026.1.5

Timelineinfo

06/11/2026 CVE reserved
07/09/2026 +28 days VulDB entry created
07/10/2026 +0 days Advisory disclosed
07/10/2026 +0 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: github.com
Status: Confirmed

CVE: CVE-2026-53961 (🔒)
GCVE (CVE): GCVE-0-2026-53961
GCVE (VulDB): GCVE-100-377341

Entryinfo

Created: 07/10/2026 00:36
Changes: 07/10/2026 00:36 (54)
Complete: 🔍
Cache ID: 216::103

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Discussion

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