CVE-2026-115723
Snap7 through 1.4.3 Out-of-Bounds Write via BRecv and CheckAsBRecvCompletion
CVSS Score
7.4
EPSS Score
0.0%
EPSS Percentile
0th
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.
| CWE | CWE-787 |
| Vendor | davenardella |
| Product | snap7 |
| Published | Oct 23, 2026 |
| Last Updated | Oct 23, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:H Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
High
Availability
High
Affected Versions
davenardella / snap7
0 ≤ 1.4.3
References
github.com: https://github.com/davenardella/snap7/pull/41 github.com: https://github.com/davenardella/snap7/blob/30f37da3114024a71ba93f7fd855c680b97a406f/src/core/s7_partner.cpp#L1126-L1166 github.com: https://github.com/davenardella/snap7/blob/30f37da3114024a71ba93f7fd855c680b97a406f/src/core/s7_partner.cpp#L850-L867 vulncheck.com: https://www.vulncheck.com/advisories/snap7-through-1.4.3-out-of-bounds-write-via-brecv-and-checkasbrecvcompletion
Credits
Telmo Xavier