TI-2026-47726 Aliases CVE-2026-67448 GHSA-8r62-w5wh-fc5m

Mailpit: WebSocket origin check bypass via percent-encoded path (regression of CVE-2026-22689)

LOW 28CWE-177Published 2026-08-20 · Updated 2026-08-21

Key facts

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

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-200 and CWE-346.

Summary

Mailpit is an email testing tool and API for developers. From 1.29.0 until 1.30.6, Mailpit's server/server.go origin middleware checks the raw RequestURI for the /api/ prefix while Go's ServeMux routes using the percent-decoded URL path, and server/websockets/client.go configures websocket.Upgrader.CheckOrigin to return true. A malicious website can request /%61pi/events, skip corsOriginAccessControl(), reach the /api/events WebSocket handler, and receive live message IDs, Message-Id values, sender and recipient fields, subjects, tags, and body snippets from an unauthenticated default Mailpit instance after the user visits the site. This is a regression of the earlier WebSocket origin protection and does not affect deployments protected by --ui-auth-file. This issue is fixed in version 1.30.6.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00221 12th percentileScored 2026-11-07

Fix Fixed mailpit (axllent): 1.30.6github.com/axllent/mailpit (Go): 1.30.6

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
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	1.29.0 to before 1.30.6	1.30.6	Patch available	CNA
—	github.com/axllent/mailpit (Go)	1.29.0 to before 1.30.6	1.30.6	Patch available	GHSA-8r62-w5wh-fc5m

mailpit Vendoraxllent Affected 1.29.0 to before 1.30.6 Fixed in 1.30.6 Patch available CNA
github.com/axllent/mailpit (Go) Vendor— Affected 1.29.0 to before 1.30.6 Fixed in 1.30.6 Patch available GHSA-8r62-w5wh-fc5m

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPE	Versions	Role	Vendor
cpe:2.3:a:axllent:mailpit::::::::	—	—	axllent

cpe:2.3:a:axllent:mailpit:*:*:*:*:*:*:*:* Versions — — ·axllent

Remediation

Fix · CNA mailpit (axllent) Fixed in 1.30.6
Fix · GHSA-8r62-w5wh-fc5m github.com/axllent/mailpit (Go) Fixed in 1.30.6 Advisory →

Timeline

2026-10-02 Threatist record created from CVE-2026-67448
2026-10-03 Alias added: GHSA-8r62-w5wh-fc5m

References

Advisory 1

https://nvd.nist.gov/vuln/detail/CVE-2026-67448

Other 4

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-2026-33450 Mailpit: Path traversal & arbitrary file write in mailpit dump --http via attacker-controlled message IDs CVSS 3.1HIGH 8.2
TI-2026-39868 Mailpit: Incomplete SSRF protection in Link Check API via IPv6 transition mechanisms (follow-up to CVE-2026-27808) CVSS 3.1MEDIUM 5.8
TI-2026-17561 Mailpit Proxy Endpoint is Vulnerable to Server-Side Request Forgery (SSRF) CVSS 3.1MEDIUM 5.8
TI-2026-47725 Mailpit: SMTP DATA line reader buffers over-limit input before size enforcement CVSS 3.1MEDIUM 5.3

See all 15 →

Sources

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