Critical Linux Kernel kernel crypto subsystem Vulnerability Scores 9.8 CVSS

Last refreshed2026-10-15

Status: UPDATED | Advisory ID: CVE-2026-31637

Key Details

CVE	CVE-2026-31637
CVSS Score / Version	9.8 (Critical) / CVSS v3.1
Updated	2026-10-15
CVSS Vector	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`
CVSS Prose	attack vector is network; attack complexity is low; privileges required is none; user interaction is none; scope is unchanged; confidentiality impact is high; integrity impact is high; availability impact is high.
Affected products	Linux Kernel and Siemens SIMATIC S7-1500 TM MFP - GNU/Linux subsystem
Exploitation prediction (EPSS)	0.59% probability of exploitation in the next 30 days (47% percentile) -- FIRST.org's EPSS model.

Vendor	Product	Affected Versions	Patch Status
Linux	Linux Kernel
Siemens	SIMATIC S7-1500 TM MFP - GNU/Linux subsystem

Vendor

Product

Affected Versions

Patch Status

Linux

Linux Kernel

Siemens

SIMATIC S7-1500 TM MFP - GNU/Linux subsystem

Subsystems	Controllers & Field I/O, OT Supporting Infrastructure
Sectors	All Sectors

In the Linux kernel, the following vulnerability has been resolved:

rxrpc: reject undecryptable rxkad response tickets

rxkad_decrypt_ticket() decrypts the RXKAD response ticket and then

parses the buffer as plaintext without checking whether

crypto_skcipher_decrypt() succeeded.

A malformed RESPONSE can therefore use a non-block-aligned ticket

length, make the decrypt operation fail, and still drive the ticket

parser with attacker-controlled bytes.

Check the decrypt result and abort the connection with RXKADBADTICKET

when ticket decryption fails. (NVD)

Monitor Linux's and Siemens's web pages for any future patch releases.

Source	Reference
NVD	https://nvd.nist.gov/vuln/detail/CVE-2026-31637
CVE	https://www.cve.org/CVERecord?id=CVE-2026-31637

Source

Reference

NVD

CVE