CVE-2026-23829 (GCVE-0-2026-23829)

Vulnerability from cvelistv5 – Published: 2026-01-18 23:23 – Updated: 2026-01-20 20:08
VLAI
Title
Mailpit has SMTP Header Injection via Regex Bypass
Summary
Mailpit is an email testing tool and API for developers. Prior to version 1.28.3, Mailpit's SMTP server is vulnerable to Header Injection due to an insufficient Regular Expression used to validate `RCPT TO` and `MAIL FROM` addresses. An attacker can inject arbitrary SMTP headers (or corrupt existing ones) by including carriage return characters (`\r`) in the email address. This header injection occurs because the regex intended to filter control characters fails to exclude `\r` and `\n` when used inside a character class. Version 1.28.3 fixes this issue.
Severity
5.3 (Medium)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
SSVC
Exploitation: poc Automatable: yes Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-01-20 20:08 UTC
CWE
  • CWE-93 - Improper Neutralization of CRLF Sequences ('CRLF Injection')
  • CWE-150 - Improper Neutralization of Escape, Meta, or Control Sequences
Assigner
GitHub_M CNA under the mitre root
CNA scorecard C 72/100 over 7861 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
axllent mailpit Affected: < 1.28.3
guessed Create a notification for this product.
Show details on NVD website
To clipboard 

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