Remote DOS via uninitialized memory access in KTLS receive
Summary
| CVE | CVE-2026-49423 |
|---|---|
| State | PUBLISHED |
| Assigner | freebsd |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-08-19 07:16:28 UTC |
| Updated | 2026-08-19 07:16:28 UTC |
| Description | When building the iovec array for a received TLS 1.2 CBC record, ktls_ocf_tls_cbc_decrypt() incremented the iovec index for every mbuf in the chain, including mbufs that were skipped because they contained only TLS header bytes. This left uninitialized entries in the iovec array. The iovec array was allocated without zeroing. A remote TLS peer can cause the kernel to read from uninitialized iovec entries during HMAC computation, resulting in a kernel panic. The peer must be able to control TCP segmentation such that the first mbuf of a CBC record contains only the 5-byte TLS record header. |
Risk And Classification
Problem Types: CWE-908 | CWE-908 CWE-908: Use of Uninitialized Resource
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | FreeBSD | FreeBSD | affected 15.1-RELEASE p1 release | Not specified |
| CNA | FreeBSD | FreeBSD | affected 15.0-RELEASE p11 release | Not specified |
| CNA | FreeBSD | FreeBSD | affected 14.4-RELEASE p7 release | Not specified |
| CNA | FreeBSD | FreeBSD | affected 14.3-RELEASE p16 release | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| security.freebsd.org/advisories/FreeBSD-SA-26:46.ktls.asc | [email protected] | security.freebsd.org | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Yuxiang Yang, Yizhou Zhao, Ao Wang, Xuewei Feng, Qi Li, and Ke Xu from Tsinghua University using GLM-5.1 from Z.ai (en)
There are currently no legacy QID mappings associated with this CVE.