# 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.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 17 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** BELL-CVE-2026-93157, DEBIAN-CVE-2026-93157, GHSA-86x5-phch-gqrh, UBUNTU-CVE-2026-93157

## 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.

## Is CVE-2026-93157 being exploited?

There is no known exploitation of CVE-2026-93157 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-93157 and fix it if it is affected.

What it is: 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.
Exploitation: There is no known exploitation of CVE-2026-93157 in the wild and no public exploit code.

Affected product: Linux. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-93157/ (Markdown: https://insights.sbomify.com/CVE-2026-93157/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-93157
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-93157
- OSV: https://osv.dev/vulnerability/CVE-2026-93157

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-93157/
Summaries are generated and may contain mistakes; the official description above is the record.