CVE-2026-57842

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

HIGH
7
CVSS Score
Published: September 11, 2026 at 01:48 PM UTC
Updated: October 1, 2026 at 03:20 PM UTC
1 product affected across 1 vendorNetBSD

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Severity
HIGH7
Exploit prediction
EPSS 0.1%
SSVC
No known exploit

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

10.0 ≤ v ≤ 10.18.0 ≤ v ≤ 8.39.0 ≤ v < 9.510.08.09.0
Affected range stops below 9.5, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

Patch and advisory references

SSVC — Action Prioritization

SSVCNo known exploitNot automatableTotal impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7HIGHVulnCheck
Attack Vector
LOCAL
Complexity
HIGH
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Vector?

Quick Info

StatusAWAITING ANALYSIS
CWE
CWE-415CWE-416

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