CVE-2026-115723: Out-of-bounds Write in davenardella snap7
Description
Snap7 versions up to and including 1.4.3 have an out-of-bounds write vulnerability in the passive partner component. This flaw allows a malicious active partner, connecting from a configured peer address, to overflow application buffers by declaring an unvalidated BSend total length. The vulnerability can cause the BRecv function to copy memory beyond the buffer, potentially crashing or corrupting SCADA, HMI, or gateway processes.
CVSS v4.0
Score 8.3high
Affected software
davenardella
snap7
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AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-115723 describes an out-of-bounds write vulnerability in Snap7 through version 1.4.3. The issue exists in the passive partner implementation where the BSend total length is not validated properly. An attacker acting as an active partner can declare a total length of up to 65535 bytes but send a shorter fragment, causing the BRecv function to perform a memcpy operation beyond the allocated buffer. This can lead to process crashes or memory corruption in critical industrial control system components such as SCADA, HMI, or gateway processes.
Potential Impact
Successful exploitation allows an unauthenticated attacker connecting from a configured peer address to cause memory corruption or crashes in SCADA, HMI, or gateway processes that use Snap7. This can disrupt industrial control system operations and potentially lead to denial of service or data integrity issues.
Mitigation Recommendations
No patch or official fix information is provided in the available data. Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, restrict network access to trusted peers only and monitor for unusual activity from configured peer addresses.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- VulnCheck
- Date Reserved
- 2026-10-23T11:26:42.748Z
- Cvss Version
- 4.0
- State
- PUBLISHED
Threat ID: 6adb4c874d27ba8daa1f3886
Added to database: 10/23/2026, 12:01:11 UTC
Last enriched: 10/23/2026, 12:15:25 UTC
Last updated: 10/23/2026, 12:15:25 UTC
Views: 4
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