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TI-2026-22161 Aliases CVE-2026-27808GHSA-mpf7-p9x7-96r3

Mailpit is Vulnerable to Server-Side Request Forgery (SSRF) via Link Check API

Priority HIGH 76CWE-918Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Information disclosure
Confidentiality · integrity · availability
High · None · None
Fix status
Fixed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA and GitHub. Impact type from CWE-918 and the CVSS impact.

Summary

Mailpit is an email testing tool and API for developers. Prior to version 1.29.2, the Link Check API (/api/v1/message/{ID}/link-check) is vulnerable to Server-Side Request Forgery (SSRF). The server performs HTTP HEAD requests to every URL found in an email without validating target hosts or filtering private/internal IP addresses. The response returns status codes and status text per link, making this a non-blind SSRF. In the default configuration (no authentication on SMTP or API), this is fully exploitable remotely with zero user interaction. This is the same class of vulnerability that was fixed in the HTML Check API (CVE-2026-23845 / GHSA-6jxm-fv7w-rw5j) and the screenshot proxy (CVE-2026-21859 / GHSA-8v65-47jx-7mfr), but the Link Check code path was not included in either fix. Version 1.29.2 fixes this vulnerability.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00532 45th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed mailpit (axllent): 1.29.2github.com/axllent/mailpit (Go): 1.29.2

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
axllentmailpitbefore 1.29.21.29.2Patch availableCNA
—github.com/axllent/mailpit (Go)before 1.29.21.29.2Patch availableGHSA-mpf7-p9x7-96r3
  • mailpit Vendoraxllent Affected before 1.29.2 Fixed in 1.29.2 Patch available CNA
  • github.com/axllent/mailpit (Go) Vendor— Affected before 1.29.2 Fixed in 1.29.2 Patch available GHSA-mpf7-p9x7-96r3

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:axllent:mailpit:*:*:*:*:*:*:*:*before 1.29.2Vulnerableaxllent
  • cpe:2.3:a:axllent:mailpit:*:*:*:*:*:*:*:* Versions before 1.29.2 Vulnerable ·axllent

Remediation

  • Fix · CNA mailpit (axllent) Fixed in 1.29.2
  • Fix · GHSA-mpf7-p9x7-96r3 github.com/axllent/mailpit (Go) Fixed in 1.29.2 Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-27808
  2. 2026-10-03 Alias added: GHSA-mpf7-p9x7-96r3

References

Exploit 1

Patch 1

Advisory 1

Other 2

  • TI-2026-33452 Mailpit: Unauthenticated remote memory-exhaustion DoS via unlimited SMTP DATA and /api/v1/send body sizes CVSS 3.1HIGH 7.5
  • TI-2026-33450 Mailpit: Path traversal & arbitrary file write in mailpit dump --http via attacker-controlled message IDs CVSS 3.1HIGH 8.2
  • TI-2026-17561 Mailpit Proxy Endpoint is Vulnerable to Server-Side Request Forgery (SSRF) CVSS 3.1MEDIUM 5.8
  • TI-2026-19194 Mailpit has SMTP Header Injection via Regex Bypass CVSS 3.1MEDIUM 5.3
  • TI-2026-33451 Race condition in axllent mailpit CVSS 3.1MEDIUM 5.9
  • TI-2026-19208 Mailpit Vulnerable to Server-Side Request Forgery (SSRF) via HTML Check API CVSS 3.1HIGH 7.5
See all 9 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences