CVE-2026-21859

MEDIUM EPSS 50.5%
Published Jan 8, 20265mo ago · Modified Jun 17, 20261w ago
5.3 CVSS 3.1
Medium
Find Similar
Published Jan 8, 2026 5mo ago
Last Modified Jun 17, 2026 1w ago

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.

CVSS Details

Base Score
5.3
Exploitability
3.9
Impact
1.4
Vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope Unchanged
Confidentiality Low
Integrity None
Availability None

Threat Intelligence

EPSS Exploit Probability
50.5% percentile
Exploit & Patch Status
Public Exploit Known
Patch Available

Weaknesses 1

CWE-918 Server-Side Request Forgery (SSRF) Validation

Affected Products 1

VendorProductVersionRange
axllentmailpit* <1.28.1

References 2

  • github.com https://github.com/axllent/mailpit/commit/3b9b470c093b3d20b7d751722c1c24f3eed2e19d
    Patch
  • github.com https://github.com/axllent/mailpit/security/advisories/GHSA-8v65-47jx-7mfr
    ExploitVendor Advisory

Remediation

  • github.com https://github.com/axllent/mailpit/commit/3b9b470c093b3d20b7d751722c1c24f3eed2e19d
    Patch