CVE-2026-109399: critical vulnerability in sbabic swupdate
SWUpdate through 2026.05.1 CMS Signature Verification Bypass via Embedded Intermediates
Published · Updated
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28Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 9.2epss 0.2%
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.
CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Affected products
sbabic · swupdateRelated CVEs — sbabic swupdate
In the same product, most dangerous first.
References
https://github.com/sbabic/swupdatehttps://github.com/sbabic/swupdate/blob/2026.05.1/crypto/swupdate_cms_verify_openssl.chttps://github.com/sbabic/swupdate/commit/e66c5640664a31668926a24c0c84b6b6570dc0d9https://groups.google.com/g/swupdate/c/dsoMcGFnEnshttps://www.vulncheck.com/advisories/swupdate-through-2026.05.1-cms-signature-verification-bypass-via-embedded-intermediates