Bug 2509443 - CVE-2026-39831 cri-o1.34: golang.org/x/crypto/ssh: Security key bypass due to missing user presence check [fedora-all]
Summary: CVE-2026-39831 cri-o1.34: golang.org/x/crypto/ssh: Security key bypass due to...
Keywords:
Status: NEW
Alias: None
Product: Fedora
Classification: Fedora
Component: cri-o1.34
Version: 45
Hardware: Unspecified
OS: Unspecified
high
high
Target Milestone: ---
Assignee: Brad Smith
QA Contact:
URL:
Whiteboard: {"flaws": ["1537af73-e36d-4a46-a18e-3...
Depends On:
Blocks: CVE-2026-39831
TreeView+ depends on / blocked
 
Reported: 2026-07-30 14:32 UTC by Guilherme de Almeida Suckevicz
Modified: 2026-08-17 15:43 UTC (History)
2 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed:
Type: ---
Embargoed:

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Description Guilherme de Almeida Suckevicz 2026-07-30 14:32:04 UTC 
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.

The Verify() method for FIDO/U2F security key types (sk-ecdsa-sha2-nistp256, sk-ssh-ed25519) did not check the User Presence flag. Signatures generated without physical touch were accepted, allowing unattended use of a hardware security key. To restore the previous behavior, return a "no-touch-required" extension in Permissions.Extensions from PublicKeyCallback.
Comment 1 Brad Smith 2026-08-04 16:04:28 UTC 
confirmed

    {
      "vulnerability": {
        "@id": "https://pkg.go.dev/vuln/GO-2026-5019",
        "name": "GO-2026-5019",
        "description": "Invoking bypass of FIDO/U2F security keys physical interaction in gola
ng.org/x/crypto/ssh",
        "aliases": [
          "CVE-2026-39831"
        ]
      },
      "products": [
        {
          "@id": "Unknown Product",
          "subcomponents": [
            {
              "@id": "pkg:golang/golang.org%2Fx%2Fcrypto.0"
            }
          ]
        }
      ],
      "status": "affected"
    },
Comment 2 Aoife Moloney 2026-08-17 15:43:21 UTC 
This bug appears to have been reported against 'rawhide' during the Fedora Linux 45 development cycle.
Changing version to 45.
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