CVE-2026-109399 (GCVE-0-2026-109399)

Vulnerability from cvelistv5 – Published: 2026-10-12 15:16 – Updated: 2026-10-12 15:16
VLAI
Title
SWUpdate through 2026.05.1 CMS Signature Verification Bypass via Embedded Intermediates
Summary
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.
Severity
9.2 (Critical)
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
8.1 (High)
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
CWE
  • CWE-295 - Improper Certificate Validation
Assigner
VulnCheck CNA under the mitre root
CNA scorecard B 84/100 over 5953 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
sbabic swupdate Affected: 0 , ≤ 2026.05.1 (custom)
    cpe:2.3:a:swupdate:swupdate:*:*:*:*:*:*:*:*
Create a notification for this product.
Date Public
2026-02-11 08:00
Credits
David Gstir (sigma star gmbh) Richard Weinberger (sigma star gmbh)
Show details on NVD website
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{
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          "product": "swupdate",
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        },
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          "tags": [
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          "url": "https://github.com/sbabic/swupdate"
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          "tags": [
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          "url": "https://www.vulncheck.com/advisories/swupdate-through-2026.05.1-cms-signature-verification-bypass-via-embedded-intermediates"
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    "datePublished": "2026-10-12T15:16:44.440Z",
    "dateReserved": "2026-10-12T14:40:48.738Z",
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    "state": "PUBLISHED"
  },
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          }
        ],
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        "lastModified": "2026-10-12T16:17:05.557",
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}



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Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
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  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



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