Use of uninitialized resource in FreeBSD - CVE-2026-49423
Published: July 1, 2026
Vulnerability identifier: #VU136017
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-49423
CWE-ID: CWE-908
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: FreeBSD Foundation
Affected software:
FreeBSD
FreeBSD
Detailed vulnerability description
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to uninitialized memory access in ktls_ocf_tls_cbc_decrypt() when processing received TLS 1.2 CBC records. A remote attacker can send network traffic that causes the kernel to read uninitialized iovec entries to cause a denial of service.
Only systems using receive-side KTLS are affected, and exploitation requires control of TCP segmentation so that the first mbuf of a CBC record contains only the 5-byte TLS record header.
How to mitigate CVE-2026-49423
Install security update from vendor's website.