Bug 2569965 (CVE-2026-125756)

Summary: CVE-2026-125756 postal-mime: postal-mime: Sender spoofing via address parser domain truncation
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerability-draftAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedKeywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in postal-mime. A remote attacker can spoof email sender addresses by sending an email with a specially crafted From header. Because the address parser improperly truncates domain names when encountering whitespace or comments, the reported sender address differs from the domain verified by email authentication mechanisms. This discrepancy allows attackers to bypass email security controls and impersonate trusted senders.
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Description OSIDB Bzimport 2026-11-10 19:27:40 UTC 
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.