CVE-2026-93157 hwrng: xilinx-trng - propagate timeout before any data is read
A bug in the Xilinx TRNG kernel driver causes incorrect error handling on timeouts, potentially leading to denial of service or data integrity issues.
- 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-2026-93157?
CVE-2026-93157 is a denial of service 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:
hwrng: xilinx-trng - propagate timeout before any data is read
xtrng_readblock32() polls for 16-byte chunks but returns the number of bytes read even when the first poll times out. Its caller then treats a zero return as a short successful read, and partial reads for full 32-byte blocks can make the tail copy use a fixed block offset rather than the amount already produced.
Return the poll error when no data has been read, preserve partial positive returns after some data is available, stop the generator on all collection exits, and append tail bytes at the current output count.
Which versions are affected by CVE-2026-93157?
How do I fix CVE-2026-93157?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-93157 being exploited?
There is no known exploitation of CVE-2026-93157 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-93157, DEBIAN-CVE-2026-93157, GHSA-86x5-phch-gqrh, UBUNTU-CVE-2026-93157.