axllent Mailpit up to 1.31.0 Deny List IsInternalIP server-side request forgery

Summaryinfo

A vulnerability classified as problematic was found in axllent Mailpit up to 1.31.0. Affected by this issue is the function IsInternalIP of the component Deny List. The manipulation results in server-side request forgery. This vulnerability is reported as CVE-2026-84697. The attack can be launched remotely. No exploit exists.

Detailsinfo

A vulnerability, which was classified as problematic, was found in axllent Mailpit up to 1.31.0. Affected is the function IsInternalIP of the component Deny List. The manipulation with an unknown input leads to a server-side request forgery vulnerability. CWE is classifying the issue as CWE-918. The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination. This is going to have an impact on confidentiality. CVE summarizes:

Mailpit's IsInternalIP deny list function fails to block the Azure WireServer address 168.63.129.16 and the RFC 2765/6145 IPv4-translated IPv6 prefix, allowing server-side request forgery to internal destinations. Attackers can supply hostnames resolving to these addresses in message content to reach the link check API and proxy endpoint for accessing internal resources.

The advisory is shared for download at github.com. This vulnerability is traded as CVE-2026-84697 since 09/02/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 09/02/2026).

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Vendor

• axllent

Name

• Mailpit

Version

• 1.0
• 1.1
• 1.2
• 1.3
• 1.4
• 1.5
• 1.6
• 1.7
• 1.8
• 1.9
• 1.10
• 1.11
• 1.12
• 1.13
• 1.14
• 1.15
• 1.16
• 1.17
• 1.18
• 1.19
• 1.20
• 1.21
• 1.22
• 1.23
• 1.24
• 1.25
• 1.26
• 1.27
• 1.28
• 1.29
• 1.30
• 1.31.0

CPE 2.3info

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CPE 2.2info

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