Buffer overflow in Davenardella Snap7
CVE-2026-115723
Snap7 through 1.4.3 contains an out-of-bounds write vulnerability in the passive partner that allows a malicious active partner to overflow application buffers by declaring an unvalidated BSend total length. Attackers connecting from the configured peer address can declare up to 65535 bytes and send a short fragment, causing BRecv to memcpy past the buffer and crash or corrupt SCADA, HMI or gateway processes.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.4 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:H.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
- github.com/davenardella/snap7/pull/41 (issue-tracking, patch)
- github.com/davenardella/snap7/blob/30f37da3114024a71ba93f7fd855c680b97a406f/src… (technical-description)
- github.com/davenardella/snap7/blob/30f37da3114024a71ba93f7fd855c680b97a406f/src… (technical-description)
- www.vulncheck.com/advisories/snap7-through-1.4.3-out-of-bounds-write-via-brecv-… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-115723?
- CVE-2026-115723 is a high-severity vulnerability in Davenardella Snap7, classified under Out-of-bounds Write. CVSS score: 7.4/10. Published 2026-10-23.
- How severe is CVE-2026-115723?
- High severity. CVSS v3 base score is 7.4 out of 10.