CVE-2026-90070 tpm: st33zp24: Return zero on status read failure
A flaw in the Linux kernel TPM driver allows uninitialized stack data to be interpreted as status flags, potentially leaking memory or causing denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-90070?
CVE-2026-90070 is a vulnerability in Linux, published on 17 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
tpm: st33zp24: Return zero on status read failure
st33zp24_status() ignores the result of the transport read and returns data even when no byte was received. The I2C transport, for example, skips i2c_master_recv() when the register-select write is short or fails, leaving data uninitialized. The resulting stack value can be interpreted as TPM_STS flags and let status checks complete spuriously.
The status callback cannot propagate a transport error. Return zero unless recv() reports exactly one byte. With no status bits set, callers retry or take their existing timeout or error path instead of acting on an invalid status value.
This issue was found by a static analysis checker and confirmed by manual source review.
Which versions are affected by CVE-2026-90070?
How do I fix CVE-2026-90070?
Apply the vendor's patch.
Is CVE-2026-90070 being exploited?
There is no known exploitation of CVE-2026-90070 in the wild and no public exploit code.
Sources
Also known as AZL-102855, BELL-CVE-2026-90070, DEBIAN-CVE-2026-90070, GHSA-q7v7-xw33-v766, UBUNTU-CVE-2026-90070.