CVE-2026-65200

3th percentile - higher than 3% of all known CVEs

The openUBMC device-management process parses PLDM-over-MCTP and NCSI-over-MCTP responses from on-bus devices, and three response parsers in the shared transport libraries subtract a fixed header or reserved-field size from a device-supplied response length without a lower-bound check. An undersized response wraps the unsigned length difference to a very large value, and the parser then reads far past the response buffer. The affected code sits in the base PLDM control class and the Huawei NCSI driver, so it is reachable for any PLDM endpoint or Huawei NIC on the internal management bus.

An attacker with access to the internal management bus could exploit the vulnerability to read out of bounds, potentially leading to data disclosure or code execution. The risk affects devices with PLDM or Huawei NICs on the management bus.

Update openUBMC to a version containing the fix that checks the lower bound of the response length. Until patched, restrict access to the internal management bus and monitor for unusual responses.