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.
Project Subscriptions
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Advisories
| Source | ID | Title |
|---|---|---|
Github GHSA |
GHSA-8r62-w5wh-fc5m | Mailpit: WebSocket origin check bypass via percent-encoded path (regression of CVE-2026-22689) |
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Thu, 20 Aug 2026 21:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | 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. | |
| Title | Mailpit: WebSocket origin check bypass via percent-encoded path (regression of CVE-2026-22689) | |
| Weaknesses | CWE-177 CWE-200 CWE-346 |
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| References |
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| Metrics |
cvssV3_1
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Projects
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Status: PUBLISHED
Assigner: GitHub_M
Published:
Updated: 2026-08-20T21:29:29.682Z
Reserved: 2026-07-29T15:07:24.992Z
Link: CVE-2026-67448
No data.
Status : Received
Published: 2026-08-20T22:17:56.870
Modified: 2026-08-20T22:17:56.870
Link: CVE-2026-67448
No data.
OpenCVE Enrichment
No data.
Github GHSA