CVE-2026-57842Public exploit

Local kernel crash via recvmsg iovec double-free

Published Sep 11, 2026 · Updated Oct 1, 2026

Use-after-free and double-free in NetBSD 8.0 through 8.3, 9.0 through 9.4, and 10.0 through 10.1 allow local users to crash the kernel via recvmsg(). In msg_recv_copyin(), a missing return on the success path falls through to cleanup, freeing the iovec buffer before its caller uses and frees it again. Exploitation requires a 32-bit binary on a 64-bit NetBSD host and msg_iovlen between 9 and IOV_MAX; the reported consequences also include kernel memory corruption.

CVSS severity7.3
High
EPSS probability0.14%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free and double-free in NetBSD 8.0 through 8.3, 9.0 through 9.4, and 10.0 through 10.1 allow local users to crash the kernel via recvmsg(). In msg_recv_copyin(), a missing return on the success path falls through to cleanup, freeing the iovec buffer before its caller uses and frees it again. Exploitation requires a 32-bit binary on a 64-bit NetBSD host and msg_iovlen between 9 and IOV_MAX; the reported consequences also include kernel memory corruption.

The record

CVE
CVE-2026-57842
Published
Sep 11, 2026
Updated
Oct 1, 2026
Vendor
The NetBSD Foundation
Product
NetBSD
Classifications
CWE-415, CWE-416, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 11, 2026CVE publishedPublication date reported by the CVE source.
  2. Oct 1, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=10.0 <=10.1
  2. Affected versionversion=8.0 <=8.3
  3. Affected versionversion=9.0 <9.5

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The NetBSD Foundation · NetBSDversion=10.0 <=10.1; version=8.0 <=8.3; version=9.0 <9.5

Published CVSS scores

7.0VulnCheck CNACVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
7.3VulnCheck CNACVSS:4.0/AV:L/AC:H/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Activity data is delayed. The latest report is Sep 28, 2026.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-415Double Free
CWE-416Use After Free
T1499.004Endpoint Denial of Service: Application or System Exploitation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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