CVE-2026-49423
Full vulnerability record from the local CVENow database.
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.
Severity
LOW
CVSS score
3.3
(v3.1)
Vulnerability status
Analyzed
Source identifier
Published
2026-08-19 07:16:28.570000
Last modified
2026-11-09 20:10:00.200000
View original CVE JSON
{
"id": "CVE-2026-49423",
"sourceIdentifier": "[email protected]",
"published": "2026-08-19T07:16:28.570",
"lastModified": "2026-11-09T20:10:00.200",
"vulnStatus": "Analyzed",
"cveTags": [],
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{
"lang": "en",
"value": "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.\n\nA 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."
},
{
"lang": "es",
"value": "Al construir el array iovec para un registro TLS 1.2 CBC recibido, ktls_ocf_tls_cbc_decrypt() incrementaba el índice iovec por cada mbuf en la cadena, incluyendo mbufs que fueron omitidos porque contenían solo bytes de cabecera TLS. Esto dejaba entradas no inicializadas en el array iovec. El array iovec fue asignado sin inicializar a cero.\n\nUn par TLS remoto puede hacer que el kernel lea de entradas iovec no inicializadas durante el cálculo de HMAC, resultando en un pánico del kernel. El par debe ser capaz de controlar la segmentación TCP de tal manera que el primer mbuf de un registro CBC contenga solo la cabecera de registro TLS de 5 bytes."
}
],
"affected": [
{
"source": "[email protected]",
"affectedData": [
{
"vendor": "FreeBSD",
"product": "FreeBSD",
"defaultStatus": "unknown",
"modules": [
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],
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"baseScore": 3.3,
"baseSeverity": "LOW",
"attackVector": "LOCAL",
"attackComplexity": "LOW",
"privilegesRequired": "LOW",
"userInteraction": "NONE",
"scope": "UNCHANGED",
"confidentialityImpact": "NONE",
"integrityImpact": "LOW",
"availabilityImpact": "NONE"
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"timestamp": "2026-08-26T17:51:26.420678Z",
"id": "CVE-2026-49423",
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"source": "[email protected]",
"type": "Secondary",
"description": [
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"references": [
{
"url": "https://security.freebsd.org/advisories/FreeBSD-SA-26:46.ktls.asc",
"source": "[email protected]",
"tags": [
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]
}
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}