CVE-2026-40355: kerberos 5 from 1.18.0 (inclusive), through 1.22.2 (inclusive); +4 more affected products

Affected technology

kerberos 5 · from 1.18.0 (inclusive), through 1.22.2 (inclusive)
mit

Kerberos 5 · 1.18 to before 1.22.3
MIT

SIMATIC S7-1500 CPU 1518-4 PN/DP MFP · V3.1.6 to before *
Siemens

SIMATIC S7-1500 CPU 1518-4 PN/DP MFP · V3.1.5 to before *
Siemens

SIMATIC S7-1500 CPU 1518-4 PN/DP MFP · V3.1.7 to before *
Siemens

SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP · V3.1.6 to before *
Siemens

SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP · V3.1.5 to before *
Siemens

SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP · V3.1.7 to before *
Siemens

SIPLUS S7-1500 CPU 1518-4 PN/DP MFP · V3.1.6 to before *
Siemens

SIPLUS S7-1500 CPU 1518-4 PN/DP MFP · V3.1.5 to before *
Siemens

SIPLUS S7-1500 CPU 1518-4 PN/DP MFP · V3.1.7 to before *
Siemens

Description’s affected range: before 1.22.3

Component: Not specified by the source

Attack conditions (Vendor/CNA, CVSS 3.1): Network (remote) · No privileges required · No user interaction required

Attack conditions (NVD, CVSS 3.1): Network (remote) · No privileges required · No user interaction required

What an attacker can do

An unauthenticated remote attacker can trigger this, causing the process to terminate in parse_nego_message. Vendor/CNA’s CVSS 3.1 assessment (base score 5.9/10) rates confidentiality and integrity impact as none; availability impact as high. NVD’s CVSS 3.1 assessment (base score 7.5/10) rates confidentiality and integrity impact as none; availability impact as high.