CVE-2026-90467

aiosmtplib before 5.1.3 ESMTP Parameter Injection via unvalidated addresses

Published Sep 12, 2026 CVSS 4.0 · 6.3 Medium EPSS < 1% KEV · Not listed
Description
aiosmtplib before 5.1.3 fails to properly validate email addresses supplied by callers, allowing attackers to inject ESMTP parameters into MAIL FROM and RCPT TO command lines. Attackers can craft malicious addresses containing spaces and angle brackets to append parameters like AUTH, NOTIFY, or ORCPT to envelope commands, forging authenticated identities or forcing delivery notifications to third parties.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Cole
Cole aiosmtplib
Vendors & Products Cole
Cole aiosmtplib
Type Values Removed Values Added
Description aiosmtplib before 5.1.3 fails to properly validate email addresses supplied by callers, allowing attackers to inject ESMTP parameters into MAIL FROM and RCPT TO command lines. Attackers can craft malicious addresses containing spaces and angle brackets to append parameters like AUTH, NOTIFY, or ORCPT to envelope commands, forging authenticated identities or forcing delivery notifications to third parties.
Title aiosmtplib before 5.1.3 ESMTP Parameter Injection via unvalidated addresses
Weaknesses CWE-88
References
Metrics cvssV3_1

{'score': 4, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:N'}

cvssV4_0

{'score': 6.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:L/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
VulnCheck
Published
Updated
Sep 14, 2026, 6:17 PM
Reserved
Sep 11, 2026, 11:36 PM
Status
Deferred
Published
Sep 12, 2026, 2:16 AM
Modified
Sep 23, 2026, 5:17 PM