CVE-2026-67447

Mailpit is an email testing tool and API for developers. From 1.30.0 until 1.30.5, Mailpit's internal/smtpd/smtpd.go readData() function calls bufio.Reader.ReadBytes before applying the len(data)+len(line) size check to the completed SMTP DATA line against Server.MaxSize. An unauthenticated SMTP client can send a single line larger than the configured MaxMessageSize, causing the full line to be allocated before Mailpit returns the 552 5.3.4 rejection. This post-fix gap remains after normal multi-line DATA accumulation was bounded, and concurrent oversized lines can create substantial memory pressure beyond the configured message-size cap. This issue is fixed in version 1.30.5.

CVSS v3 5.3 MEDIUM

5.3^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 3.9 / Impact : 1.4

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact LOW

Scope UNCHANGED

References

Link	Resource
https://github.com/axllent/mailpit/commit/8720c6bd8281fc00d458081908f1dbef8e59a98c
https://github.com/axllent/mailpit/releases/tag/v1.30.5
https://github.com/axllent/mailpit/security/advisories/GHSA-r553-m4fv-5v97
https://github.com/axllent/mailpit/security/advisories/GHSA-r553-m4fv-5v97

Configurations

No configuration.

History

No history.

Information

Published : 2026-08-20 22:17

Updated : 2026-08-21 17:16

NVD link : CVE-2026-67447

Mitre link : CVE-2026-67447

CVE.ORG link : CVE-2026-67447

JSON object : View

Products Affected

No product.

CWE

CWE-770

Allocation of Resources Without Limits or Throttling

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