CVE-2026-67448: Information Disclosure (CVSS 6.5)

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.

Is your site exposed to CVE-2026-67448?

Run a free security scan — no signup, results in seconds.

CVSS v3.1 Score

6.5

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N

EPSS — Exploit Prediction

0.0015

Probability of exploitation

0.04%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-177 CWE-177

CWE-200 CWE-200

CWE-346 CWE-346

References

Other References

https://github.com/axllent/mailpit/commit/fbe5e006c3f1682b819df58b4a932d7a84920be9 https://github.com/axllent/mailpit/releases/tag/v1.30.6 https://github.com/axllent/mailpit/security/advisories/GHSA-8r62-w5wh-fc5m

Frequently Asked Questions

What is CVE-2026-67448? +

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. It has a CVSS v3.1 base score of 6.5 (MEDIUM).

How severe is CVE-2026-67448? +

CVE-2026-67448 has a CVSS v3.1 score of 6.5 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0015, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-67448? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

Related Vulnerabilities

CVE-2024-23983

Improper handling of canonical URL-encoding may lead to bypass not properly constrained by request rules.

CVE-2026-41041 9.1

URL path injection via unencoded user-supplied identifiers vulnerability in Apache Gravitino. This issue affects Apache Gravitino: from 1.0.0 before 1.2.1. …

CVE-2026-59083 9.1

Improper Handling of URL Encoding (Hex Encoding) vulnerability in Apache Tomcat's rewrite valve allowed security constraint bypass for some configurations. …

CVE-2026-76172 7.5

fast-uri is a URI parser for Node.js. During parsing it runs a legacy decoding pass over the scheme component and …

CVE-2026-6414 5.9

@fastify/static versions 8.0.0 through 9.1.0 decode percent-encoded path separators (%2F) before filesystem resolution, while Fastify's router treats them as literal …

CVE-2024-48866 5.3

An improper handling of URL encoding (Hex Encoding) vulnerability has been reported to affect several QNAP operating system versions. If …

CVE-2026-67448