CVE-2026-45712

Mailpit is an email testing tool and API for developers. Prior to version 1.30.0, the screenshot/print proxy (/proxy?data=…) maintains a package-level assets map[string]MessageAssets cache, but reads the map without holding assetsMutex while a long-running cleanup goroutine and (re-entrant) CSS-rewriting code path concurrently write to it under the lock. When the unsynchronized read coincides with a synchronized write, Go's runtime raises fatal error: concurrent map read and map write — a runtime.throw that is not recoverable by http.Server's handler-panic recover. The whole Mailpit process exits, taking the SMTP, POP3 and HTTP listeners down with it. Version 1.30.0 contains a patch.

CVSS v3 5.9 MEDIUM

5.9^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 2.2 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity HIGH

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://github.com/axllent/mailpit/releases/tag/v1.30.0	Release Notes
https://github.com/axllent/mailpit/security/advisories/GHSA-w4vj-r5pg-3722	Exploit Vendor Advisory
https://github.com/axllent/mailpit/security/advisories/GHSA-w4vj-r5pg-3722	Exploit Vendor Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:axllent:mailpit:*:*:*:*:*:*:*:*

History

28 Jul 2026, 15:27

Type	Values Removed	Values Added
First Time		Axllent mailpit Axllent
References	~~() https://github.com/axllent/mailpit/releases/tag/v1.30.0 -~~	() https://github.com/axllent/mailpit/releases/tag/v1.30.0 - Release Notes
References	~~() https://github.com/axllent/mailpit/security/advisories/GHSA-w4vj-r5pg-3722 -~~	() https://github.com/axllent/mailpit/security/advisories/GHSA-w4vj-r5pg-3722 - Exploit, Vendor Advisory
CPE		cpe:2.3:a:axllent:mailpit::::::::

20 Jul 2026, 16:17

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-07-20 16:17

Updated : 2026-07-28 15:27

NVD link : CVE-2026-45712

Mitre link : CVE-2026-45712

CVE.ORG link : CVE-2026-45712

JSON object : View

Products Affected

axllent

mailpit

CWE

CWE-362

Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

CWE-770

Allocation of Resources Without Limits or Throttling

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