CVE-2026-90467

MEDIUMPre-NVD 4.04.0—
EchelonGraph scoreHIGH confidence

Score 4.0 from GitHub Security Advisory published 2026-09-12. a secondary CVSS source baseline 4.0; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 3 sources updated this week
4.0EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 4.0Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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.

CVSS v3
4.0
EG Score
4.0(high)
EG Risk
18(Track)
EG Risk 18/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity40% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
14%
KEV
Not listed

Published

September 12, 2026

Last Modified

September 14, 2026

Advisory Details (5)

Auto-updated Sep 12, 2026
Patch available. Sources: github_commit, github_release.
generic

aiosmtplib before 5.1.3 ESMTP Parameter Injection via unvalidated addresses | Advisories | VulnCheck

https://www.vulncheck.com/advisories/aiosmtplib-before-5.1.3-esmtp-parameter-injection-via-unvalidated-addresses
generic

GitHub - cole/aiosmtplib: asyncio smtplib implementation · GitHub

https://github.com/cole/aiosmtplib
generic

aiosmtplib/src/aiosmtplib/email.py at v5.1.2 · cole/aiosmtplib · GitHub

https://github.com/cole/aiosmtplib/blob/v5.1.2/src/aiosmtplib/email.py
github_release Patch Available

v5.1.3

Patch available: cole/aiosmtplib v5.1.3

https://github.com/cole/aiosmtplib/releases/tag/v5.1.3
github_commit Patch Available

commit 2e1b21071497 (cole/aiosmtplib)

Patch available: cole/aiosmtplib v5.1.3 (contains commit 2e1b21071497)

https://github.com/cole/aiosmtplib/commit/2e1b210714974ccc9efd0d09a8f846cb9aeaaec2

Vendor Advisories for CVE-2026-90467(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 22× in last 7d / 26× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-09-18 21:17 UTCEG score recompute
  2. 2026-09-18 21:17 UTCGHSA enrichment
  3. 2026-09-18 19:28 UTCEPSS rescore
  4. 2026-09-17 20:14 UTCEG score recompute
  5. 2026-09-17 20:14 UTCGHSA enrichment
  6. 2026-09-17 19:32 UTCEPSS rescore
  7. 2026-09-16 19:59 UTCEG score recompute
  8. 2026-09-16 19:59 UTCGHSA enrichment
  9. 2026-09-16 14:09 UTCEPSS rescore
  10. 2026-09-16 05:15 UTCEPSS rescore
  11. 2026-09-15 19:41 UTCEG score recompute
  12. 2026-09-15 19:41 UTCGHSA enrichment
  13. 2026-09-15 03:12 UTCEPSS rescore
  14. 2026-09-14 19:21 UTCEG score recompute
  15. 2026-09-14 19:21 UTCGHSA enrichment
  16. 2026-09-14 18:28 UTCEG score recompute
  17. 2026-09-14 18:28 UTCGHSA enrichment
  18. 2026-09-14 02:50 UTCEG score recompute
  19. 2026-09-14 02:50 UTCGHSA enrichment
  20. 2026-09-13 16:48 UTCEPSS rescore
  21. 2026-09-13 02:35 UTCEG score recompute
  22. 2026-09-13 02:35 UTCGHSA enrichment
  23. 2026-09-12 15:02 UTCEPSS rescore
  24. 2026-09-12 02:19 UTCEG score recompute
  25. 2026-09-12 01:59 UTCEG score recompute
Show 1 more
  1. 2026-09-12 01:58 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-90467?
CVE-2026-90467 is a medium vulnerability published on September 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…
When was CVE-2026-90467 disclosed?
CVE-2026-90467 was first published in the National Vulnerability Database on September 12, 2026, with the most recent update on September 14, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-90467 actively exploited?
CVE-2026-90467 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 86.0% of all scored CVEs.
What is the CVSS score of CVE-2026-90467?
CVE-2026-90467 has a CVSS v3 base score of 4.0 (NVD).
How do I remediate CVE-2026-90467?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-90467, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2026-90467

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