Critical 9.8Published Oct 9, 2026

CVE-2026-15340Savannah lwIP SMTP client Classic Buffer Overflow

Updated under an hour ago (2026-10-19 07:50 UTC)

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It affects Savannah lwIP SMTP client. Add what you run to find out whether that includes you.

EPSS puts the chance of exploitation in the next 30 days at 0.60%, higher than 48% of scored CVEs.

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Every CVE for Savannah lwIP SMTP client

Exploited in the last 30 days

lwIP SMTP client does not check the size of inputs, potentially allowing a buffer overflow.

CVSS: 9.8 CRITICAL (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness (CWE): CWE-120
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): 0.60% (percentile 48)
Assigned by: icscert
NVD analysis: Awaiting Analysis
Record last updated: Oct 11, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Savannah lwIP SMTP client savannah:lwip_smtp_client (from the name)	2.2.1; patch_125_smtp_txbuf.diff not affected; git commit (614420f82c8729d070e01464c0dddb3c9525c772) not affected	CNA record

References

https://www.cisa.gov/news-events/ics-advisories/icsa-26-279-02
https://github.com/cisagov/CSAF/blob/develop/csaf_files/OT/white/2026/icsa-26-279-02.json

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.