Answer in brief
CVE-2026-90467 records a Medium severity (CVSS 6.3) vulnerability in aiosmtplib before 5.1.3 ESMTP Parameter Injection via unvalidated addresses. The current sources do not mark it as known exploited. The current feed maps cole/aiosmtplib (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 6.3. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps cole/aiosmtplib (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| cole/aiosmtplibgeneric | >=0 <5.1.3 | 5.1.3 |
Published upstream
Sep 12, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Sep 23, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Sep 12, 2026
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.
Quoted source text, attributed separately from HOL analysis.