CVE-2026-57842
NetBSD COMPAT_NETBSD32 Double Free / Use-After-Free via recvmsg() msg_iovlen
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.
INFO
Published Date :
Sept. 11, 2026, 2:17 p.m.
Last Modified :
Sept. 11, 2026, 2:17 p.m.
Remotely Exploit :
No
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-57842
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 3.1 | HIGH | [email protected] | ||||
| CVSS 4.0 | HIGH | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 4.0 | HIGH | [email protected] |
Solution
- Update NetBSD to the latest version.
- Apply relevant security patches promptly.
- Reboot the system after updates.
- Test the fix in a non-production environment.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-57842.
| URL | Resource |
|---|---|
| https://gnats.netbsd.org/60373 | |
| https://www.vulncheck.com/advisories/netbsd-compat-netbsd32-double-free-use-after-free-via-recvmsg-msg-iovlen |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-57842 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-57842
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-57842 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-57842 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by [email protected]
Sep. 11, 2026
Action Type Old Value New Value Added 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. Added CVSS V4.0 AV:L/AC:H/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CVSS V3.1 AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H Added CWE CWE-415 Added CWE CWE-416 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/57xxx/CVE-2026-57842.json">CVE-2026-57842</a> Added Reference https://gnats.netbsd.org/60373 Added Reference https://www.vulncheck.com/advisories/netbsd-compat-netbsd32-double-free-use-after-free-via-recvmsg-msg-iovlen