useplunk up to 0.8.x Webhook Request /webhooks/sns signature verification

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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7.6$0-$5k0.00

Summaryinfo

A vulnerability labeled as critical has been found in useplunk plunk up to 0.8.x. The impacted element is an unknown function of the file /webhooks/sns of the component Webhook Request Handler. The manipulation results in signature verification. This vulnerability was named CVE-2026-42193. The attack may be performed from remote. There is no available exploit. The affected component should be upgraded.

Detailsinfo

A vulnerability classified as critical has been found in useplunk plunk up to 0.8.x. Affected is an unknown part of the file /webhooks/sns of the component Webhook Request Handler. The manipulation with an unknown input leads to a signature verification vulnerability. CWE is classifying the issue as CWE-347. The product does not verify, or incorrectly verifies, the cryptographic signature for data. This is going to have an impact on integrity, and availability. CVE summarizes:

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.

The advisory is available at github.com. This vulnerability is traded as CVE-2026-42193 since 04/25/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. Technical details are known, but there is no available exploit.

Upgrading to version 0.9.0 eliminates this vulnerability. The upgrade is hosted for download at github.com.

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Productinfo

Vendor

Name

Version

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.8
VulDB Meta Temp Score: 7.6

VulDB Base Score: 6.5
VulDB Temp Score: 6.2
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 9.1
CNA Vector (GitHub_M): 🔒

CVSSv2info

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

Exploitinginfo

Class: Signature verification
CWE: CWE-347 / CWE-345
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: plunk 0.9.0

Timelineinfo

04/25/2026 CVE reserved
05/09/2026 +14 days Advisory disclosed
05/09/2026 +0 days VulDB entry created
05/09/2026 +0 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: GHSA-9792-w86v-gx53
Status: Confirmed

CVE: CVE-2026-42193 (🔒)
GCVE (CVE): GCVE-0-2026-42193
GCVE (VulDB): GCVE-100-362358

Entryinfo

Created: 05/09/2026 06:47
Changes: 05/09/2026 06:47 (66)
Complete: 🔍
Cache ID: 216::103

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