Mailpit: Path traversal & arbitrary file write in mailpit dump --http via attacker-controlled message IDs
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Code execution
- Confidentiality · integrity · availability
- None · High · Low
- Fix status
- Fixed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and GitHub. Impact type from CWE-829.
Summary
Mailpit is an email testing tool and API for developers. Prior to version 1.30.0, the mailpit dump --http <base-url> <out-dir> sub-command downloads every message from a remote Mailpit instance and writes each one as <id>.eml inside the user-supplied output directory. The message ID field is taken verbatim from the JSON response of the remote server and concatenated into the output path with path.Join, which silently normalizes `..` segments. A malicious HTTP server impersonating Mailpit can therefore make mailpit dump write attacker-controlled bytes to any path the running user can write, fully outside the intended output directory. Version 1.30.0 contains a patch.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| axllent | mailpit | before 1.30.0 | 1.30.0 | Patch available | CNA |
| — | github.com/axllent/mailpit (Go) | before 1.30.0 | 1.30.0 | Patch available | GHSA-qx5x-85p8-vg4j |
- mailpit Vendoraxllent Affected before 1.30.0 Fixed in 1.30.0 Patch available CNA
- github.com/axllent/mailpit (Go) Vendor— Affected before 1.30.0 Fixed in 1.30.0 Patch available GHSA-qx5x-85p8-vg4j
Remediation
- Fix · CNA mailpit (axllent) Fixed in 1.30.0
- Fix · GHSA-qx5x-85p8-vg4j github.com/axllent/mailpit (Go) Fixed in 1.30.0 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2026-45711
- 2026-10-03 Alias added: GHSA-qx5x-85p8-vg4j
References
More axllent Mailpit vulnerabilities
- TI-2026-22161 Mailpit is Vulnerable to Server-Side Request Forgery (SSRF) via Link Check API CVSS 3.1HIGH 8.6
- 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-2026-17561 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
Sources
- CVE-2026-45711 · CVE Program
- CVE-2026-45711 · NVD
- FIRST EPSS
- GHSA-qx5x-85p8-vg4j · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences