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CVE-2026-49423

Remote DOS via uninitialized memory access in KTLS receive

Published
Last modified
published
Not listed in CISA KEV
Fix
Fixed in p1, p11, p7, p16
None on Exploit-DB, Metasploit or GitHub
  • Exploitation: none
  • Automatable: no
  • Technical impact: partial

Summary

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.

Timeline

  1. CVE published
  2. CISA SSVC assessment

    Exploitation: none · Automatable: no · Technical impact: partial

  3. Record last updated

Affected versions

  • FreeBSD FreeBSD

    From 15.1-RELEASE · fixed in p1; From 15.0-RELEASE · fixed in p11; From 14.4-RELEASE · fixed in p7; From 14.3-RELEASE · fixed in p16

References 1

security.freebsd.org