Double Free in The NetBSD Foundation
CVE-2026-57842
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.
Vulnerability class: Double Free
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.0 (High). Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.001 (3.0th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 3rd percentile — 3.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.001 · newest: 0.001 · change: 0.000
Affected products
Weakness classification (CWE)
References
- gnats.netbsd.org/60373 (vendor-advisory, patch)
- www.vulncheck.com/advisories/netbsd-compat-netbsd32-double-free-use-after-free-… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-57842?
- CVE-2026-57842 is a high-severity vulnerability in The NetBSD Foundation, classified under Double Free. CVSS score: 7.0/10. Published 2026-09-11.
- How severe is CVE-2026-57842?
- High severity. CVSS v3 base score is 7.0 out of 10.