CVE-2026-125756
postal-mime before 4.2.1 Sender Spoofing via Address Parser Domain Truncation
CVSS Score
5.9
EPSS Score
0.0%
EPSS Percentile
0th
postal-mime before 4.2.1 contains a parser differential vulnerability in its address parser that truncates the domain at folding whitespace or comments preceding a dot. Remote attackers can craft From headers that pass SPF/DKIM/DMARC alignment for their own subdomain while PostalMime.parse() reports a spoofed victim sender address.
| CWE | CWE-436 |
| Vendor | postalsys |
| Product | postal-mime |
| Published | Nov 10, 2026 |
| Last Updated | Nov 10, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
High
Availability
None
Affected Versions
postalsys / postal-mime
0 < 4.2.1
References
github.com: https://github.com/postalsys/postal-mime/security/advisories/GHSA-jh3p-792r-98gm github.com: https://github.com/postalsys/postal-mime/commit/646725704463839f233472453b7c8306bd1dde21 github.com: https://github.com/postalsys/postal-mime/releases/tag/v4.2.1 github.com: https://github.com/postalsys/postal-mime/blob/939a220bd518f54d98a088c315d7227e6215cae3/src/address-parser.ts#L265 vulncheck.com: https://www.vulncheck.com/advisories/postal-mime-before-4.2.1-sender-spoofing-via-address-parser-domain-truncation
Credits
Ismail Can Guner