Description
Plunk is an open-source email platform built on top of AWS SES. Prior to version 0.9.0, the /webhooks/sns endpoint accepts Amazon SNS notification payloads from unauthenticated requests without verifying the SNS signature, certificate, or topic ARN, meaning anyone can forge a valid-looking webhook request. This allows an unauthenticated attacker to spoof SNS events to trigger workflow automations, unsubscribe contacts, manipulate email delivery metrics, and potentially exhaust billing credits. This issue has been patched in version 0.9.0.
References (2)
Core 2
Core References
X_Refsource_Confirm x_refsource_confirm
https://github.com/useplunk/plunk/security/advisories/GHSA-9792-w86v-gx53
X_Refsource_Misc x_refsource_misc
https://github.com/useplunk/plunk/releases/tag/v0.9.0
Scores
CVSS v3
9.1
EPSS
0.0013
EPSS Percentile
2.7%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
CISA SSVC
Vulnrichment
Exploitation
none
Automatable
yes
Technical Impact
total
Details
CWE
CWE-347
Status
published
Products (1)
useplunk/plunk
< 0.9.0
Published
May 08, 2026
Tracked Since
May 09, 2026