---
title: "CVE-2026-57842: NetBSD - Use After Free"
description: "NetBSD contains a use-after-free and double-free vulnerability caused by a missing return statement in msg_recv_copyin() within the COMPAT_NETBSD32 layer, letting local users trigger kernel panic or memory corruption by calling recvmsg() with specific msg_iovlen values."
url: https://panop.io/threat-heartbeat/CVE-2026-57842/
---

# CVE-2026-57842 NetBSD - Use After Free

NetBSD contains a use-after-free and double-free vulnerability caused by a missing return statement in msg\_recv\_copyin() within the COMPAT\_NETBSD32 layer, letting local users trigger kernel panic or memory corruption by calling recvmsg() with specific msg\_iovlen values.

CVSS base score 7.0 /10

High

CISA KEV

Not listed

Public exploit

None known

Authentication

Required

EPSS

0.14% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-57842)

## Details

Type

Use After Free

Impact

Denial Of Service

CVSS vector

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

Published

11 September 2026

Updated

15 October 2026

Weakness

[CWE-415](https://cwe.mitre.org/data/definitions/415.html)

## Vendor fix

Update to the latest NetBSD version with the fix applied.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

## References

- [https://nvd.nist.gov/vuln/detail/CVE-2026-57842](https://nvd.nist.gov/vuln/detail/CVE-2026-57842)
- [https://gnats.netbsd.org/60373](https://gnats.netbsd.org/60373)
- [https://www.vulncheck.com/advisories/netbsd-compat-netbsd32-double-free-use-after-free-via-recvmsg-msg-iovlen](https://www.vulncheck.com/advisories/netbsd-compat-netbsd32-double-free-use-after-free-via-recvmsg-msg-iovlen)

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## What this record can't tell you

- Whether you run the affected software, and where
- Whether an attacker can actually reach and exploit it
- The misconfigurations that never get a CVE number
- What it would cost the business, ranked into what to fix first

Panop answers these inside your environment, for this CVE and every other finding.

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