CVE-2026-14986 zephyrproject CVE debrief

Who should care

Defenders responsible for ITE it51xxx I2C driver deployments, particularly those using Zephyr, should assess exposure and prioritize patching or compensating controls. This includes operators, platform administrators, vulnerability management teams, and security teams who need to verify I2C target buffer mode configuration and monitor I2C bus activity for suspicious transactions.

Why it matters

The ITE it51xxx I2C driver buffer overflow vulnerability requires prompt attention from defenders to prevent potential crashes or code execution. Affected deployments should prioritize patching or implementing compensating controls.

• Potential controller crash or code execution
• Requires verification of I2C target buffer mode configuration
• Necessitates monitoring of I2C bus activity for suspicious transactions

Technical summary

The ITE it51xxx I2C driver, when operating as an I2C target in buffer mode, copies host-supplied write data into a fixed-size buffer without a pre-write bounds check. This allows a malicious or misbehaving I2C master to trigger an out-of-bounds write, potentially crashing the controller or leading to code execution. The fix adds a pre-write bounds check in target_i2c_fifo_read_to_buf() that aborts and resets the FIFO before any out-of-bounds store. The vulnerability requires prompt attention from defenders to prevent potential crashes or code execution.

Defensive priority

High

Recommended defensive actions

• Review and apply the patch from the Zephyr project repository
• Verify the I2C target buffer mode configuration and adjust as needed
• Monitor I2C bus activity for suspicious transactions
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented.
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up.
• Plan vendor-supported updates or mitigations through normal change control where exposure is confirmed.

Evidence notes

The vulnerability is caused by a missing pre-write bounds check in the target_i2c_fifo_read_to_buf() function. The fix adds this check to abort and reset the FIFO before any out-of-bounds store. The ITE it51xxx I2C driver, when operating as an I2C target in buffer mode, copies host-supplied write data into a fixed-size buffer without a pre-write bounds check. This allows a malicious or misbehaving I2C master to trigger an out-of-bounds write, potentially crashing the controller or leading to code execution. The running index data->w_

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.