CVE-2026-109399

high

SWUpdate through 2026.05.1 contains an improper certificate validation vulnerability in crypto/swupdate_cms_verify_openssl.c that trusts untrusted X.509 certif…

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

8.1

8.1 (CVSS v3.1)

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

Severity source: NVD CVSS v3.1 (disclosure@vulncheck.com)

Timeline (UTC)

Published: 2026-10-12 16:17

Modified: 2026-10-18 12:17

NVD status: Deferred

Last synced 1 day ago

Verified against the source API 2026-10-27 06:58 UTC

Exploitation

Not listed in CISA KEV (as of last catalog sync)

Absence from KEV does not mean a CVE is not exploited. Exploitation status: unknown (no authoritative evidence in our sources).

Affected products

Not reported by the source (unknown — not "none").

Weakness classification (CWE)

CWE-295

Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.

Mitigation & advisories

No vendor advisory or patch reference tagged by NVD. Check the references below.

References

https://github.com/sbabic/swupdate disclosure@vulncheck.com
https://github.com/sbabic/swupdate/blob/2026.05.1/crypto/swupdate_cms_verify_openssl.c disclosure@vulncheck.com
https://github.com/sbabic/swupdate/commit/e66c5640664a31668926a24c0c84b6b6570dc0d9 disclosure@vulncheck.com
https://groups.google.com/g/swupdate/c/dsoMcGFnEns disclosure@vulncheck.com
https://www.vulncheck.com/advisories/swupdate-through-2026.05.1-cms-signature-verification... disclosure@vulncheck.com

Data sources

NVD CVE API 2.0 — fetched 2026-10-27 06:58 UTC · record ↗

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