CVE-2026-78659: HTTP/2 server memory exhaustion due to Trailer headers in net/http

Published Oct 8, 2026
·
Updated

HTTP/2 server memory exhaustion due to Trailer headers in net/http

Other sources

When "Trailer" headers are sent by a client, the HTTP server internally uses the header values to populate the Request.Trailer map passed to the server handler. Because Request.Trailer is a map, each entry incurs memory overhead. For HTTP/2 servers, a malicious client can exploit this by sending a "Trailer" header that declares a large number of fields, causing the server to allocate a disproportionate amount of memory while bypassing Server.MaxHeaderValueCount and Server.MaxHeaderBytes limits. This exploit is not applicable for HTTP/1 servers, which do not support multiplexing a large number of requests over one TCP connection, and whose Server.MaxHeaderBytes are calculated differently.

— NVD

Affected Software

67 affected componentsFixes available
go net/http
All of the following
azurelinux/prometheus-process-exporter<0.8.2-6
0.8.2-6
Microsoft Azure Linux=3.0
All of the following
azurelinux/prometheus-node-exporter<1.7.0-6
1.7.0-6
Microsoft Azure Linux=3.0
All of the following
azurelinux/git-lfs<3.6.1-7
3.6.1-7
Microsoft Azure Linux=3.0
All of the following
azurelinux/coredns<1.11.4-23
1.11.4-23
Microsoft Azure Linux=3.0
All of the following
azurelinux/gh<2.102.0-2
2.102.0-2
Microsoft Azure Linux=3.0
All of the following
azurelinux/vitess<19.0.4-15
19.0.4-15
Microsoft Azure Linux=3.0
All of the following
azurelinux/opa<0.63.0-6
0.63.0-6
Microsoft Azure Linux=3.0
All of the following
azurelinux/application-gateway-kubernetes-ingress<1.7.7-7
1.7.7-7
Microsoft Azure Linux=3.0
All of the following
azurelinux/jx<3.10.182-6
3.10.182-6
Microsoft Azure Linux=3.0
All of the following
azurelinux/etcd<3.5.35-1
3.5.35-1
Microsoft Azure Linux=3.0
All of the following
azurelinux/packer<1.9.5-23
1.9.5-23
Microsoft Azure Linux=3.0
All of the following
azurelinux/prometheus-adapter<0.12.0-12
0.12.0-12
Microsoft Azure Linux=3.0
All of the following
azurelinux/keda<2.14.1-22
2.14.1-22
Microsoft Azure Linux=3.0
All of the following
azurelinux/kubevirt<1.8.4-4
1.8.4-4
Microsoft Azure Linux=3.0
All of the following
azurelinux/kube-vip-cloud-provider<0.0.10-11
0.0.10-11
Microsoft Azure Linux=3.0
All of the following
azurelinux/containerd2<2.3.7-1
2.3.7-1
Microsoft Azure Linux=3.0
All of the following
azurelinux/kured<1.15.0-7
1.15.0-7
Microsoft Azure Linux=3.0
All of the following
azurelinux/containerized-data-importer<1.62.0-9
1.62.0-9
Microsoft Azure Linux=3.0
All of the following
azurelinux/flannel<0.24.2-34
0.24.2-34
Microsoft Azure Linux=3.0
All of the following
azurelinux/influxdb<2.7.5-22
2.7.5-22
Microsoft Azure Linux=3.0
All of the following
azurelinux/docker-compose<2.27.0-16
2.27.0-16
Microsoft Azure Linux=3.0
All of the following
azurelinux/azurelinux-image-tools<1.7.0-2
1.7.0-2
Microsoft Azure Linux=3.0
All of the following
azurelinux/cert-manager<1.12.15-15
1.12.15-15
Microsoft Azure Linux=3.0
All of the following
azurelinux/cloud-provider-kubevirt<0.5.1-10
0.5.1-10
Microsoft Azure Linux=3.0
All of the following
azurelinux/skopeo<1.14.4-14
1.14.4-14
Microsoft Azure Linux=3.0
All of the following
azurelinux/docker-buildx<0.14.0-19
0.14.0-19
Microsoft Azure Linux=3.0
All of the following
azurelinux/telegraf<1.31.0-35
1.31.0-35
Microsoft Azure Linux=3.0
All of the following
azurelinux/multus<4.0.2-12
4.0.2-12
Microsoft Azure Linux=3.0
All of the following
azurelinux/kata-containers<4.1.0.kata1-2
4.1.0.kata1-2
Microsoft Azure Linux=3.0
All of the following
azurelinux/kata-containers-cc<3.15.0.aks0-23
3.15.0.aks0-23
Microsoft Azure Linux=3.0
All of the following
azurelinux/kubernetes<1.30.10-32
1.30.10-32
Microsoft Azure Linux=3.0
All of the following
azurelinux/moby-containerd-cc<1.7.7-19
1.7.7-19
Microsoft Azure Linux=3.0
alpine/docker<29.9.0-r0
29.9.0-r0
alpine/go<1.26.9-r0
1.26.9-r0

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade azurelinux/prometheus-node-exporter to a version that resolves this vulnerability.

    Fixed in 1.7.0-6
  2. Upgrade

    Upgrade azurelinux/git-lfs to a version that resolves this vulnerability.

    Fixed in 3.6.1-7
  3. Upgrade

    Upgrade azurelinux/prometheus-process-exporter to a version that resolves this vulnerability.

    Fixed in 0.8.2-6
  4. Upgrade

    Upgrade azurelinux/coredns to a version that resolves this vulnerability.

    Fixed in 1.11.4-23
  5. Upgrade

    Upgrade azurelinux/vitess to a version that resolves this vulnerability.

    Fixed in 19.0.4-15
  6. Upgrade

    Upgrade azurelinux/gh to a version that resolves this vulnerability.

    Fixed in 2.102.0-2
  7. Upgrade

    Upgrade azurelinux/application-gateway-kubernetes-ingress to a version that resolves this vulnerability.

    Fixed in 1.7.7-7
  8. Upgrade

    Upgrade azurelinux/etcd to a version that resolves this vulnerability.

    Fixed in 3.5.35-1
  9. Upgrade

    Upgrade azurelinux/opa to a version that resolves this vulnerability.

    Fixed in 0.63.0-6
  10. Upgrade

    Upgrade azurelinux/jx to a version that resolves this vulnerability.

    Fixed in 3.10.182-6
  11. Upgrade

    Upgrade azurelinux/packer to a version that resolves this vulnerability.

    Fixed in 1.9.5-23
  12. Upgrade

    Upgrade azurelinux/prometheus-adapter to a version that resolves this vulnerability.

    Fixed in 0.12.0-12
  13. Upgrade

    Upgrade azurelinux/kubevirt to a version that resolves this vulnerability.

    Fixed in 1.8.4-4
  14. Upgrade

    Upgrade azurelinux/keda to a version that resolves this vulnerability.

    Fixed in 2.14.1-22
  15. Upgrade

    Upgrade azurelinux/containerd2 to a version that resolves this vulnerability.

    Fixed in 2.3.7-1
  16. Upgrade

    Upgrade azurelinux/kured to a version that resolves this vulnerability.

    Fixed in 1.15.0-7
  17. Upgrade

    Upgrade azurelinux/kube-vip-cloud-provider to a version that resolves this vulnerability.

    Fixed in 0.0.10-11
  18. Upgrade

    Upgrade azurelinux/flannel to a version that resolves this vulnerability.

    Fixed in 0.24.2-34
  19. Upgrade

    Upgrade azurelinux/containerized-data-importer to a version that resolves this vulnerability.

    Fixed in 1.62.0-9
  20. Upgrade

    Upgrade azurelinux/docker-compose to a version that resolves this vulnerability.

    Fixed in 2.27.0-16
  21. Upgrade

    Upgrade azurelinux/influxdb to a version that resolves this vulnerability.

    Fixed in 2.7.5-22
  22. Upgrade

    Upgrade azurelinux/azurelinux-image-tools to a version that resolves this vulnerability.

    Fixed in 1.7.0-2
  23. Upgrade

    Upgrade azurelinux/cert-manager to a version that resolves this vulnerability.

    Fixed in 1.12.15-15
  24. Upgrade

    Upgrade azurelinux/cloud-provider-kubevirt to a version that resolves this vulnerability.

    Fixed in 0.5.1-10
  25. Upgrade

    Upgrade azurelinux/skopeo to a version that resolves this vulnerability.

    Fixed in 1.14.4-14
  26. Upgrade

    Upgrade azurelinux/docker-buildx to a version that resolves this vulnerability.

    Fixed in 0.14.0-19
  27. Upgrade

    Upgrade azurelinux/telegraf to a version that resolves this vulnerability.

    Fixed in 1.31.0-35
  28. Upgrade

    Upgrade azurelinux/multus to a version that resolves this vulnerability.

    Fixed in 4.0.2-12
  29. Upgrade

    Upgrade azurelinux/kata-containers to a version that resolves this vulnerability.

    Fixed in 4.1.0.kata1-2
  30. Upgrade

    Upgrade azurelinux/kata-containers-cc to a version that resolves this vulnerability.

    Fixed in 3.15.0.aks0-23
  31. Upgrade

    Upgrade azurelinux/kubernetes to a version that resolves this vulnerability.

    Fixed in 1.30.10-32
  32. Upgrade

    Upgrade azurelinux/moby-containerd-cc to a version that resolves this vulnerability.

    Fixed in 1.7.7-19
  33. Upgrade

    Upgrade alpine/docker to a version that resolves this vulnerability.

    Fixed in 29.9.0-r0
  34. Upgrade

    Upgrade alpine/go to a version that resolves this vulnerability.

    Fixed in 1.26.9-r0

Event History

Oct 8, 2026
CVE Published
via MITRE·10:53 PM
Data Sourced
via MITRE·10:53 PM
DescriptionWeakness
Data Sourced
via NVD·11:17 PM
DescriptionSeverityWeakness
Data Sourced
via OSV·11:17 PM
DescriptionSeverityAffected Software
Oct 11, 2026
Data Sourced
via Microsoft·08:23 AM
DescriptionSeverityWeaknessAffected Software

Frequently Asked Questions

1

Which server deployments are exposed to this issue?

HTTP/2 servers using Go's net/http are exposed. HTTP/1 servers are not affected by this exploit because they cannot multiplex a large number of requests over one TCP connection and calculate Server.MaxHeaderBytes differently.

2

What does an attacker need to do to trigger the memory exhaustion?

A malicious client needs to send HTTP/2 requests containing a Trailer header that declares a large number of fields. The server creates entries in Request.Trailer for those declared fields, consuming disproportionate memory.

3

Do Server.MaxHeaderValueCount or Server.MaxHeaderBytes prevent this attack?

No. For HTTP/2, the declared Trailer fields can cause the allocation while bypassing both Server.MaxHeaderValueCount and Server.MaxHeaderBytes limits.

Company

Resources

Contact

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