Bug 2509478 - CVE-2026-39831 moby-engine: golang.org/x/crypto/ssh: Security key bypass due to missing user presence check [fedora-all]
Summary: CVE-2026-39831 moby-engine: golang.org/x/crypto/ssh: Security key bypass due ...
Keywords:
Status: CLOSED NOTABUG
Alias: None
Product: Fedora
Classification: Fedora
Component: moby-engine
Version: rawhide
Hardware: Unspecified
OS: Unspecified
high
high
Target Milestone: ---
Assignee: Brad Smith
QA Contact: Fedora Extras Quality Assurance
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: 2026-07-30 21:52 UTC (History)
6 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed: 2026-07-30 21:52:08 UTC
Type: ---
Embargoed:

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Description Guilherme de Almeida Suckevicz 2026-07-30 14:34:57 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 2026-07-30 21:52:08 UTC 
cli [ 29.x] Elapsed: 2s
❯ go mod why -m golang.org/x/crypto/ssh
# golang.org/x/crypto/ssh
(main module does not need module golang.org/x/crypto/ssh)

cli [ 29.x]
❯ cd ../moby/

moby [ docker-29.x][?]
❯ go mod why -m golang.org/x/crypto/ssh
# golang.org/x/crypto/ssh
(main module does not need module golang.org/x/crypto/ssh)
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