Bug 2509475 - CVE-2026-39831 gh: golang.org/x/crypto/ssh: Security key bypass due to missing user presence check [fedora-all]
Summary: CVE-2026-39831 gh: golang.org/x/crypto/ssh: Security key bypass due to missin...
Keywords:
Status: CLOSED ERRATA
Alias: None
Product: Fedora
Classification: Fedora
Component: gh
Version: rawhide
Hardware: Unspecified
OS: Unspecified
high
high
Target Milestone: ---
Assignee: Mikel Olasagasti Uranga
QA Contact:
URL:
Whiteboard: {"flaws": ["1537af73-e36d-4a46-a18e-3...
Depends On:
Blocks: CVE-2026-39831
TreeView+ depends on / blocked
 
Reported: 2026-07-30 14:34 UTC by Guilherme de Almeida Suckevicz
Modified: 2026-08-02 00:56 UTC (History)
4 users (show)

Fixed In Version: gh-2.97.0-2.fc44
Clone Of:
Environment:
Last Closed: 2026-08-02 00:56:04 UTC
Type: ---
Embargoed:


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Description Guilherme de Almeida Suckevicz 2026-07-30 14:34:43 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 Fedora Update System 2026-07-31 09:53:47 UTC
FEDORA-2026-4e77362489 (gh-2.97.0-2.fc44) has been submitted as an update to Fedora 44.
https://bodhi.fedoraproject.org/updates/FEDORA-2026-4e77362489

Comment 2 Fedora Update System 2026-08-01 15:55:38 UTC
FEDORA-2026-4e77362489 has been pushed to the Fedora 44 testing repository.
Soon you'll be able to install the update with the following command:
`sudo dnf upgrade --enablerepo=updates-testing --refresh --advisory=FEDORA-2026-4e77362489`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2026-4e77362489

See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.

Comment 3 Fedora Update System 2026-08-02 00:56:04 UTC
FEDORA-2026-4e77362489 (gh-2.97.0-2.fc44) has been pushed to the Fedora 44 stable repository.
If problem still persists, please make note of it in this bug report.


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