CVE-2026-49423 json
Remote DOS via uninitialized memory access in KTLS receive
published 2026-08-19 2 mo ago modified 2026-08-31 2 mo ago also EUVD-2026-62344
- cvss
- 3.3
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.1%
- EPSS 0.1% chance of exploitation in 30 days, percentile 3%
- public exploits
- 0
- none known
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.
Patch / fix
- FreeBSD FreeBSD p1, p7, p11, p16
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 2 mo ago
Exploit prediction
0.14% chance of exploitation in the next 30 days, higher than 3% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CISA ADP | 3.1 | 3.3 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N |
| CNA | 3.1 | 3.3 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N |
Affected products
- FreeBSD FreeBSD
Classification
- Weakness
-
- CWE-908 Use of Uninitialized Resource
References
-
security.freebsd.org
/advisories/FreeBSD-SA-26:46.ktls.asc
vendor-advisory
Sources
- CVE List CVE-2026-49423
- NVD CVE-2026-49423
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.