CriticalCritical vulnerability

CVE-2026-109399 (CVSS 9.2)

NVD · officialPublished Oct 12, 2026Risk 50/100

SWUpdate through 2026.05.1 contains an improper certificate validation vulnerability in crypto/swupdate_cms_verify_openssl.c that trusts untrusted X.509 certificates embedded in CMS SignedData for chain building. Attackers holding a signing key from a sibling intermediate under the same root can embed that intermediate in the signature to install malicious updates.

Technical details

CVSS

9.2

AV:NetworkAC:HighPR:NoneUI:None

Evidence and sources

This record is attributed to NVD. Exploitation status and remediation guidance are kept separate from the vulnerability's technical severity.

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