NetBSD COMPAT_NETBSD32 Double Free / Use-After-Free via recvmsg() msg_iovlen (CVE-2026-57842) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-57842

NetBSD COMPAT_NETBSD32 Double Free / Use-After-Free via recvmsg() msg_iovlen

Answer in brief

CVE-2026-57842 records a Unknown severity vulnerability in NetBSD COMPAT_NETBSD32 Double Free / Use-After-Free via recvmsg() msg_iovlen. The current sources do not mark it as known exploited. The current feed maps The NetBSD Foundation/NetBSD (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 11, 2026Updated Sep 11, 2026Source checked Sep 11, 2026First seen by HOL Sep 11, 2026Material review Sep 11, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Available

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps The NetBSD Foundation/NetBSD (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
The NetBSD Foundation/NetBSDgeneric	8.0 \|\| >=9.0 <9.5 \|\| 10.0	9.5

Recommended response

Check inventory. Check lockfiles and deployed manifests for The NetBSD Foundation/NetBSD.
Review the reported fix. Update The NetBSD Foundation/NetBSD to 9.5 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 11, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 11, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 11, 2026

Sources and claim methodology

Upstream source description

NetBSD contains a use-after-free and double-free vulnerability in msg_recv_copyin() within the COMPAT_NETBSD32 compatibility layer due to a missing return statement before the cleanup label on the success path. Any local user able to execute a 32-bit binary on a 64-bit NetBSD system can trigger a kernel panic or memory corruption by calling recvmsg() with msg_iovlen between 9 and IOV_MAX, causing the kernel to access a freed iovec buffer and subsequently free the same allocation a second time.

Quoted source text, attributed separately from HOL analysis.