CVE-2026-56854: CWE-863: Incorrect Authorization in golang.org/x/crypto golang.org/x/crypto/ssh
Description
CVE-2026-56854 is a high-severity authorization vulnerability in the golang.org/x/crypto/ssh package. The flaw involves incorrect enforcement of the source-address restriction in authentication callbacks, where this restriction was only applied to some authentication paths but ignored in others. This inconsistency could allow unauthorized access if source-address restrictions are used as a security control.
CVSS v3.1
Score 7.5high
Affected software
golang.org/x/crypto
golang.org/x/crypto/ssh
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability CVE-2026-56854 in golang.org/x/crypto/ssh arises from improper authorization checks related to the source-address critical option in authentication callbacks. While the source-address restriction is enforced on certain authentication paths, other paths do not enforce it, leading to a potential bypass of source-address-based access controls. This could result in unauthorized access when relying on source-address restrictions for authentication decisions.
Potential Impact
An attacker could bypass source-address restrictions in the authentication process, potentially gaining unauthorized access to systems relying on this control. The CVSS score of 7.5 (high) reflects the network attack vector, low complexity, no privileges required, no user interaction, and high confidentiality impact. There is no indication of integrity or availability impact.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. No official fix or patch links are provided in the available data. Users should monitor the golang.org/x/crypto project advisories for updates and apply any official fixes once available. Until then, consider additional compensating controls if source-address restrictions are critical to your security posture.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- Go
- Date Reserved
- 2026-06-23T15:10:49.353Z
- State
- PUBLISHED
Threat ID: 6a91ab5bacd9273b490abfa6
Added to database: 08/28/2026, 15:38:03 UTC
Last enriched: 09/17/2026, 02:49:41 UTC
Last updated: 10/13/2026, 18:48:21 UTC
Views: 176
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