PatchTheCVECVE-2026-79976: The MCTP-over-I2C+GPIO target binding in subsys/pmci/mctp/mctp_i2c_gpio_target.c emulates a small pseudo-regis
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Routine
HIGH 7.1
CVE-2026-79976 is a high-severity flaw (CVSS 7.1) affecting affected software. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
The MCTP-over-I2C+GPIO target binding in subsys/pmci/mctp/mctp_i2c_gpio_target.c emulates a small pseudo-register file, where the bus controller first writes a register number and then writes or reads payload bytes. The selected register (b->reg_addr) and the data-phase flag (b->rxtx) were never cleared when the controller issued an I2C STOP, so after a completed transfer the target still had a data register selected while the packet buffer that
Why this priority
- High severity
No fix is published yet: follow the downgrade or mitigation steps.
Risk facts
| CVSS score | 7.1 (High) |
| Attack vector | Adjacent network |
| Attack complexity | Low |
| Privileges needed | None |
| User interaction | None |
| EPSS exploit chance | 0.2% (top 90%) |
| CISA exploited list | No |
| Weakness | CWE-476 |
| Published | 2026-10-21 |
| Last modified | 2026-10-23 |
Publisher (CNA): Zephyr Project
Timeline
- Published CVE record published
- Updated Record last modified
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Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.