CVE-2026-67447: medium-severity vulnerability in axllent mailpit
Mailpit: SMTP DATA line reader buffers over-limit input before size enforcement
Published · Updated
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13Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 5.3epss 0.5%
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:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Affected products
axllent · mailpitRelated CVEs — axllent mailpit
In the same product, most dangerous first.
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