CVE-2026-21859

5.8 MEDIUM
Published: January 08, 2026 Modified: February 02, 2026
View on NVD

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.

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CVSS v3.x Details

0.0 Low Medium High Critical 10.0
Vector String
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N

References to Advisories, Solutions, and Tools

Patch Vendor Advisory Exploit Third Party Advisory
https://github.com/axllent/mailpit/security/advisories/GHSA-8v65-47jx-7mfr
Source: security-advisories@github.com
Exploit Vendor Advisory
https://github.com/axllent/mailpit/security/advisories/GHSA-8v65-47jx-7mfr
Source: 134c704f-9b21-4f2e-91b3-4a467353bcc0
Exploit Vendor Advisory

3 reference(s) from NVD

Quick Stats

CVSS v3 Score
5.8 / 10.0
EPSS (Exploit Probability)
1.0%
77th percentile
Exploitation Status
Not in CISA KEV

Weaknesses (CWE)

Affected Vendors

axllent