CVE-2026-115723
Snap7 through 1.4.3 contains an out-of-bounds write vulnerability in the passive partner that…
- Risk score
- 59/100
- CVSS
- 7.4 v3.1
- Exploit chance (30 days)
- 0.6%
- Published
- 23 Oct 2026
Open in the live forecast Today's forecast
What to know
- What it is
- 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, …
- Affected
- See advisory
- Fix
- Apply the vendor's security update; see the linked advisory.
- Exploitation
- No known exploitation
Why it is Yellow
- CVSS 7.4 high
- Remotely exploitable without logging in
References
- https://github.com/davenardella/snap7/blob/30f37da3114024a71ba93f7fd855c680b97a406f/src/core/s7_partner.cpp#L1126-L1166
- https://github.com/davenardella/snap7/blob/30f37da3114024a71ba93f7fd855c680b97a406f/src/core/s7_partner.cpp#L850-L867
- https://github.com/davenardella/snap7/pull/41
- https://www.vulncheck.com/advisories/snap7-through-1.4.3-out-of-bounds-write-via-brecv-and-checkasbrecvcompletion
Original description
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.
Last activity 23 Oct 2026. Patch Forecast updates every hour.