CVE-2026-39827: CWE-401: Missing Release of Memory after Effective Lifetime in golang.org/x/crypto golang.org/x/crypto/ssh
CVE-2026-39827 is a medium severity vulnerability in the golang.org/x/crypto/ssh package that causes a memory leak. When an authenticated SSH client repeatedly opens channels that the server rejects, the rejected channels are not properly removed from the server's internal state. This leads to unbounded memory growth, which can crash the server process and disrupt all connected users.
AI Analysis
Technical Summary
This vulnerability (CVE-2026-39827) in golang.org/x/crypto/ssh involves improper memory management where rejected SSH channels remain in the server's internal state instead of being released. This results in a memory leak that grows unbounded when an authenticated client repeatedly attempts to open channels that the server rejects. The leak can cause the server process to crash, impacting availability for all connected users. The CVSS score is 6.5 (medium severity) with an attack vector of network, low attack complexity, requiring low privileges, no user interaction, and impacts availability only.
Potential Impact
The vulnerability causes unbounded memory growth on the SSH server when handling rejected channel requests from authenticated clients. This can lead to server process crashes and denial of service, disrupting all connected users. There is no impact on confidentiality or integrity according to the CVSS vector.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. No official fix or temporary workaround is currently documented. Until a fix is available, limit exposure by restricting authenticated client access or monitoring for abnormal channel open requests if possible.
CVE-2026-39827: CWE-401: Missing Release of Memory after Effective Lifetime in golang.org/x/crypto golang.org/x/crypto/ssh
Description
CVE-2026-39827 is a medium severity vulnerability in the golang.org/x/crypto/ssh package that causes a memory leak. When an authenticated SSH client repeatedly opens channels that the server rejects, the rejected channels are not properly removed from the server's internal state. This leads to unbounded memory growth, which can crash the server process and disrupt all connected users.
CVSS v3.1
Score 6.5medium
Affected software
Run on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability (CVE-2026-39827) in golang.org/x/crypto/ssh involves improper memory management where rejected SSH channels remain in the server's internal state instead of being released. This results in a memory leak that grows unbounded when an authenticated client repeatedly attempts to open channels that the server rejects. The leak can cause the server process to crash, impacting availability for all connected users. The CVSS score is 6.5 (medium severity) with an attack vector of network, low attack complexity, requiring low privileges, no user interaction, and impacts availability only.
Potential Impact
The vulnerability causes unbounded memory growth on the SSH server when handling rejected channel requests from authenticated clients. This can lead to server process crashes and denial of service, disrupting all connected users. There is no impact on confidentiality or integrity according to the CVSS vector.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. No official fix or temporary workaround is currently documented. Until a fix is available, limit exposure by restricting authenticated client access or monitoring for abnormal channel open requests if possible.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- Go
- Date Reserved
- 2026-04-07T18:13:03.528Z
- Cvss Version
- null
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a0fcdabe1370fbb487d4ff6
Added to database: 05/22/2026, 03:29:47 UTC
Last enriched: 07/08/2026, 13:55:26 UTC
Last updated: 07/09/2026, 07:52:30 UTC
Views: 148
Community Reviews
0 reviewsCrowdsource mitigation strategies, share intel context, and vote on the most helpful responses. Sign in to add your voice and help keep defenders ahead.
Want to contribute mitigation steps or threat intel context? Sign in or create an account to join the community discussion.
Actions
Updates to AI analysis require Pro Console access. Upgrade inside Console → Billing.
Need more coverage?
Upgrade to Pro Console for AI refresh and higher limits.
For incident response and remediation, OffSeq services can help resolve threats faster.
Latest Threats
Check if your credentials are on the dark web
Instant breach scanning across billions of leaked records. Free tier available.