Unauthorized signing via ignored confirmation constraint
Published May 22, 2026 · Updated May 22, 2026
Constraint bypass in golang.org/x/crypto/ssh/agent before 0.52.0 allows attackers to sign data through an in-memory keyring. keyring.Add accepts an AddedKey with ConfirmBeforeUse set, while the keyring never checks that flag before Sign returns a signature. Exploitation requires an affected application to use NewKeyring with ConfirmBeforeUse and the attacker to reach that application's agent interface.
Summary
What happened
Constraint bypass in golang.org/x/crypto/ssh/agent before 0.52.0 allows attackers to sign data through an in-memory keyring. keyring.Add accepts an AddedKey with ConfirmBeforeUse set, while the keyring never checks that flag before Sign returns a signature. Exploitation requires an affected application to use NewKeyring with ConfirmBeforeUse and the attacker to reach that application's agent interface.
The record
- CVE
- CVE-2026-39833
- Published
- May 22, 2026
- Updated
- May 22, 2026
- Vendor
- golang.org/x/crypto
- Product
- golang.org/x/crypto/ssh/agent
- Classifications
- CWE-862
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- May 22, 2026CVE publishedPublication date reported by the CVE source.
- May 22, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
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- Affected versionversion=0 <0.52.0
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
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Weakness, pattern, technique
Public exploit references
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Technologies
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Your stack
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