CVE-2026-39827: Invoking memory leak when rejecting channels can lead to DoS in golang.org/x/crypto/ssh

Published May 22, 2026
·
Updated

An authenticated SSH client that repeatedly opened channels which were rejected by the server caused unbounded memory growth, eventually crashing the server process and affecting all connected users. Rejected channels are now properly removed from the connection's internal state and released for garbage collection.

Other sources

Invoking memory leak when rejecting channels can lead to DoS in golang.org/x/crypto/ssh

— Microsoft

Affected Software

33 affected componentsFixes available
go/golang.org/x/crypto/ssh
Golang Crypto Go<0.52.0
Microsoft azl3 cert-manager 1.12.15-6
Patch available
Microsoft azl3 packer 1.9.5-13
Patch available
Microsoft azl3 kubevirt 1.7.1-2
Patch available
Microsoft azl3 moby-engine 25.0.3-17
Patch available
Microsoft azl3 kubernetes 1.30.10-23
Patch available
Microsoft azl3 kubernetes 1.30.10-25
Patch available
Microsoft azl3 moby-engine 25.0.3-18
Patch available
Microsoft azl3 gh 2.62.0-16
Patch available
Microsoft azl3 telegraf 1.31.0-22
Patch available
Microsoft azl3 docker-compose 2.27.0-11
Patch available
Microsoft azl3 cf-cli 8.7.11-6
Patch available
Microsoft azl3 docker-buildx 0.14.0-13
Patch available
go/golang.org/x/crypto/ssh<0.52.0
0.52.0
Microsoft azl3 gh 2.62.0-17<2.62.0-17
2.62.0-17
Microsoft azl3 cf-cli 8.7.11-6<8.7.11-7
8.7.11-7
Microsoft azl3 telegraf 1.31.0-22<1.31.0-23
1.31.0-23
Microsoft azl3 docker-compose 2.27.0-11<2.27.0-13
2.27.0-13
Microsoft azl3 gh 2.62.0-16<2.62.0-17
2.62.0-17
Microsoft azl3 moby-engine 25.0.3-18<25.0.3-18
25.0.3-18
Microsoft azl3 kubernetes 1.30.10-25<1.30.10-25
1.30.10-25
Microsoft azl3 moby-engine 25.0.3-17<25.0.3-18
25.0.3-18
Microsoft azl3 kubernetes 1.30.10-23<1.30.10-25
1.30.10-25
Microsoft azl3 kubevirt 1.7.1-2<1.7.1-5
1.7.1-5
Microsoft azl3 packer 1.9.5-13<1.9.5-14
1.9.5-14
Microsoft azl3 cert-manager 1.12.15-6<1.12.15-8
1.12.15-8
Microsoft azl3 cf-cli 8.7.11-7<8.7.11-7
8.7.11-7
Microsoft azl3 docker-buildx 0.14.0-13<0.14.0-15
0.14.0-15
Microsoft azl3 telegraf 1.31.0-23<1.31.0-23
1.31.0-23
Microsoft azl3 gh 2.62.0-18<2.62.0-17
2.62.0-17
IBM Db2 Genius Hub<=1.1, 1.1.1, 1.1.2
IBM Agentics<=1.0

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade go/golang.org/x/crypto/ssh to a version that resolves this vulnerability.

    Fixed in 0.52.0
  2. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 8.7.11-7
  3. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 2.62.0-17
  4. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 1.31.0-23
  5. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 2.27.0-13
  6. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 25.0.3-18
  7. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 1.30.10-25
  8. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 1.7.1-5
  9. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 1.9.5-14
  10. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 1.12.15-8
  11. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 0.14.0-15

Event History

May 22, 2026
CVE Published
via MITRE·02:31 AM
Data Sourced
via MITRE·02:31 AM
DescriptionWeakness
Data Sourced
via Red Hat·04:01 AM
DescriptionSeverityAffected Software
Data Sourced
via NVD·04:16 AM
DescriptionSeverityWeaknessAffected Software
May 27, 2026
Data Sourced
via Microsoft·08:14 AM
DescriptionSeverityWeaknessAffected Software
Updated
via Microsoft·08:14 AM
Affected Software
Updated
via Microsoft·08:14 AM
DescriptionSeverity
Updated
via Microsoft·08:14 AM
DescriptionSeverityWeakness
Jun 25, 2026
Advisory Published
via GitHub·10:15 PM
Data Sourced
via GitHub·10:15 PM
DescriptionSeverityWeaknessAffected Software
Jul 13, 2026
Data Sourced
via IBM·12:00 AM
DescriptionAffected Software

Parent advisories

This vulnerability appears in the following advisories.

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Frequently Asked Questions

1

What is the severity of CVE-2026-39827?

CVE-2026-39827 has a risk rating of 45, indicating a moderate level of severity.

2

How do I fix CVE-2026-39827?

To fix CVE-2026-39827, ensure that you update to the latest version of golang.org/x/crypto/ssh where the memory leak has been addressed.

3

What causes the memory leak in CVE-2026-39827?

The memory leak in CVE-2026-39827 is caused by an authenticated SSH client repeatedly opening channels that are rejected by the server.

4

What are the potential consequences of CVE-2026-39827?

The potential consequences of CVE-2026-39827 include unbounded memory growth leading to denial of service (DoS) for the affected server.

5

Who is affected by CVE-2026-39827?

Users of the golang.org/x/crypto/ssh library who utilize authenticated SSH clients are affected by CVE-2026-39827.

Company

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Contact

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