CVE-2026-109399
SWUpdate through 2026.05.1 contains an improper certificate validation vulnerability in…
- Risk score
- 66/100
- CVSS
- 8.1 v3.1
- Exploit chance (30 days)
- 0.2%
- Published
- 12 Oct 2026
Open in the live forecast Today's forecast
What to know
- What it is
- 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 intermediat…
- Affected
- See advisory
- Fix
- Apply the vendor's security update; see the linked advisory.
- Exploitation
- No known exploitation
Why it is Amber
- CVSS 8.1 high
- Remotely exploitable without logging in
- On your watchlist: openssl
References
- https://github.com/sbabic/swupdate
- https://github.com/sbabic/swupdate/blob/2026.05.1/crypto/swupdate_cms_verify_openssl.c
- https://github.com/sbabic/swupdate/commit/e66c5640664a31668926a24c0c84b6b6570dc0d9
- https://groups.google.com/g/swupdate/c/dsoMcGFnEns
- https://www.vulncheck.com/advisories/swupdate-through-2026.05.1-cms-signature-verification-bypass-via-embedded-intermediates
Original description
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.
Last activity 12 Oct 2026. Patch Forecast updates every hour.