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.
Published: 2026-09-12
Score: 6.3 Medium
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

No vendor fix or workaround currently provided.

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Tracking

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Advisories

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History

Sat, 12 Sep 2026 02:00:00 +0000

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'}

Subscriptions

No data.

cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-09-12T01:50:34.534Z

Reserved: 2026-09-11T23:36:20.310Z

Link: CVE-2026-90467

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-09-12T02:16:24.770

Modified: 2026-09-12T02:16:24.770

Link: CVE-2026-90467

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-09-12T09:45:11Z

Weaknesses