cvedb.io
CVE-2026-11826
HIGH · CVSS 8.8
EPSS exploitation probability: 0%
Published 2026-07-18T14:17:11.480 · Last modified 2026-07-18T14:17:11.480

Summary

OpenPLC_v3 contains a heap-based buffer overflow in the getData() function in webserver/core/modbus_master.cpp. getData() reads characters between two delimiters into a caller-supplied buffer with no size parameter and no bounds check. In parseConfig() the function is invoked with the 100-byte heap-allocated MB_device.dev_name field. An authenticated attacker with access to the OpenPLC web interface can send a crafted HTTP POST to the /modbus endpoint with an oversized device_name value; the value is persisted to mbconfig.cfg and parsed on load, overflowing dev_name and overwriting adjacent struct fields (protocol at offset 108, dev_address at offset 109, ip_port at offset 210). A 200-byte payload writes 100 bytes past the allocation. The result is heap corruption leading to runtime crash

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References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.