CVE-2026-90467: Improper Neutralization of Argument Delimiters in a Command ('Argument Injection') in cole aiosmtplib
CVE-2026-90467 is a vulnerability in the aiosmtplib library before version 5.1.3 where improper validation of email addresses allows attackers to inject ESMTP parameters into MAIL FROM and RCPT TO commands. This can enable attackers to forge authenticated identities or manipulate delivery notifications by appending parameters such as AUTH, NOTIFY, or ORCPT. The vulnerability has a medium severity with a CVSS score of 6.3.
AI Analysis
Technical Summary
The aiosmtplib library versions prior to 5.1.3 do not properly neutralize argument delimiters in email addresses supplied by callers. This flaw permits attackers to inject additional ESMTP parameters into MAIL FROM and RCPT TO command lines by crafting malicious email addresses containing spaces and angle brackets. Such injection can lead to forged authenticated identities or forced delivery notifications to unintended third parties.
Potential Impact
Attackers can exploit this vulnerability to manipulate SMTP envelope commands, potentially forging authenticated sender identities or causing delivery notifications to be sent to third parties. This may affect email delivery behavior and trustworthiness of sender information, but does not directly allow code execution or system compromise.
Mitigation Recommendations
Upgrade aiosmtplib to version 5.1.3 or later where this vulnerability is fixed. No other mitigation is indicated. Patch status is confirmed by the version boundary provided.
CVE-2026-90467: Improper Neutralization of Argument Delimiters in a Command ('Argument Injection') in cole aiosmtplib
Description
CVE-2026-90467 is a vulnerability in the aiosmtplib library before version 5.1.3 where improper validation of email addresses allows attackers to inject ESMTP parameters into MAIL FROM and RCPT TO commands. This can enable attackers to forge authenticated identities or manipulate delivery notifications by appending parameters such as AUTH, NOTIFY, or ORCPT. The vulnerability has a medium severity with a CVSS score of 6.3.
CVSS v4.0
Score 6.3medium
Affected software
cole
aiosmtplib
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AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The aiosmtplib library versions prior to 5.1.3 do not properly neutralize argument delimiters in email addresses supplied by callers. This flaw permits attackers to inject additional ESMTP parameters into MAIL FROM and RCPT TO command lines by crafting malicious email addresses containing spaces and angle brackets. Such injection can lead to forged authenticated identities or forced delivery notifications to unintended third parties.
Potential Impact
Attackers can exploit this vulnerability to manipulate SMTP envelope commands, potentially forging authenticated sender identities or causing delivery notifications to be sent to third parties. This may affect email delivery behavior and trustworthiness of sender information, but does not directly allow code execution or system compromise.
Mitigation Recommendations
Upgrade aiosmtplib to version 5.1.3 or later where this vulnerability is fixed. No other mitigation is indicated. Patch status is confirmed by the version boundary provided.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- VulnCheck
- Date Reserved
- 2026-09-11T23:36:20.310Z
- Cvss Version
- 4.0
- State
- PUBLISHED
Threat ID: 6aa4b2a355bf5e2cf5bacd0f
Added to database: 09/12/2026, 02:02:11 UTC
Last enriched: 09/12/2026, 02:19:24 UTC
Last updated: 09/12/2026, 03:11:10 UTC
Views: 5
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