CVE-2026-90467
MEDIUM
NVD
CVSS Score
4
Severity
MEDIUM
Published
Sep 12, 2026
Vendor
unknown
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.
References
- https://github.com/cole/aiosmtplib
- https://github.com/cole/aiosmtplib/blob/v5.1.2/src/aiosmtplib/email.py
- https://github.com/cole/aiosmtplib/commit/2e1b210714974ccc9efd0d09a8f846cb9aeaaec2
- https://github.com/cole/aiosmtplib/releases/tag/v5.1.3
- https://www.vulncheck.com/advisories/aiosmtplib-before-5.1.3-esmtp-parameter-injection-via-unvalidated-addresses