CVE-2026-90467CWE-88

CVE-2026-90467

Medium · published September 12, 2026

CVSS v3.1
4.0
EPSS
0%
Percentile
32.2
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
4.0 · MEDIUM
Vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:N
CVSS v4.0
6.3 · 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
EPSS
0.00393 · 32.2th percentile
Weakness
CWE-88 · Improper Neutralization of Argument Delimiters in a Command ('Argument Injection')
Published
2026-09-12T06:16Z
References (5)
https://github.com/cole/aiosmtplib · [email protected]https://github.com/cole/aiosmtplib/blob/v5.1.2/src/aiosmtplib/email.py · [email protected]https://github.com/cole/aiosmtplib/commit/2e1b210714974ccc9efd0d09a8f846cb9aeaaec2 · [email protected]https://github.com/cole/aiosmtplib/releases/tag/v5.1.3 · [email protected]https://www.vulncheck.com/advisories/aiosmtplib-before-5.1.3-esmtp-parameter-injection-via-unvalidated-addresses · [email protected]
EPSS history
Timeline
  • 13 SEP 03:23Z
    EPSS moved — → 0%
    epss
  • 12 SEP 01:50Z
    aiosmtplib before 5.1.3 ESMTP Parameter Injection via unvalidated addresses
    cvelistv5