CVE-2026-39834 (Critical) detected in golang.org/x/crypto-v0.49.0

[mend-bolt-for-github]

CVE-2026-39834 - Critical Severity Vulnerability

Vulnerable Library - golang.org/x/crypto-v0.49.0

Library home page: https://proxy.golang.org/golang.org/x/crypto/@⁠v/v0.49.0.zip

Path to dependency file: /engine/go.mod

Path to vulnerable library: /home/wss-scanner/go/pkg/mod/cache/download/golang.org/x/crypto/@⁠v/v0.49.0.mod

Dependency Hierarchy:

• ❌ golang.org/x/crypto-v0.49.0 (Vulnerable Library)

Found in base branch: master

Vulnerability Details

When writing data larger than 4GB in a single Write call on an SSH channel, an integer overflow in the internal payload size calculation caused the write loop to spin indefinitely, sending empty packets without making progress. The size comparison now uses int64 to prevent truncation.

Publish Date: 2026-05-22

URL: CVE-2026-39834

CVSS 3 Score Details (9.1)

Base Score Metrics:

• Exploitability Metrics:
  • Attack Vector: Network
  • Attack Complexity: Low
  • Privileges Required: None
  • User Interaction: None
  • Scope: Unchanged
• Impact Metrics:
  • Confidentiality Impact: None
  • Integrity Impact: High
  • Availability Impact: High

For more information on CVSS3 Scores, click here.

Suggested Fix

Type: Upgrade version

Origin: https://pkg.go.dev/vuln/GO-2026-5020

Release Date: 2026-05-22

Fix Resolution: golang.org/x/crypto - v0.52.0,https://github.com/golang/crypto.git - v0.52.0

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