CVE-2026-21859

MEDIUM

5.8

Description

Mailpit is an email testing tool and API for developers. Versions 1.28.0 and below have a Server-Side Request Forgery (SSRF) vulnerability in the /proxy endpoint, allowing attackers to make requests to internal network resources. The /proxy endpoint validates http:// and https:// schemes, but it does not block internal IP addresses, enabling attackers to access internal services and APIs. This vulnerability is limited to HTTP GET requests with minimal headers. The issue is fixed in version 1.28.1.

CVE Details

CVSS v3.1 Score5.8

SeverityMEDIUM

CVSS VectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N

Attack VectorNETWORK

ComplexityLOW

Privileges RequiredNONE

User InteractionNONE

Published1/8/2026

Last Modified2/2/2026

Sourcenvd

Honeypot Sightings0

Affected Products

axllent:mailpit

Weaknesses (CWE)

CWE-918

References

https://github.com/axllent/mailpit/commit/3b9b470c093b3d20b7d751722c1c24f3eed2e19d(security-advisories@github.com)

https://github.com/axllent/mailpit/security/advisories/GHSA-8v65-47jx-7mfr(security-advisories@github.com)

https://github.com/axllent/mailpit/security/advisories/GHSA-8v65-47jx-7mfr(134c704f-9b21-4f2e-91b3-4a467353bcc0)

IOC Correlations

No correlations recorded

This product uses data from the NVD API but is not endorsed or certified by the NVD.