Vulnerability · Published Oct 8, 2026 · Assigned by Go

CVE-2026-78669Excessive CPU consumption from repeated initial window changes in net/http

High 7.5

In plain English

A high-severity security flaw in net/http from Go standard library. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 50% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)7.5High
Exploit odds (30 days)0.6%top 50.4% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official description

A malicious HTTP/2 peer can cause excessive CPU consumption in the client or server by opening a large number of streams and then sending many small SETTINGS frames containing SETTINGS_INITIAL_WINDOW_SIZE values.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
AlmaLinux:10buildah2:1.43.1-7.el10_2ALSA-2026:88262
AlmaLinux:10buildah-tests2:1.43.1-7.el10_2ALSA-2026:88262
AlmaLinux:10delve1.26.1-3.el10_2ALSA-2026:95519
AlmaLinux:8delve1.26.1-1.module_el8.10.0+4307+6e4cbc60ALSA-2026:86203
AlmaLinux:10go-toolset1.26.10-1.el10_2.alma.1ALSA-2026:86093
AlmaLinux:8go-toolset1.26.10-1.module_el8.10.0+4307+6e4cbc60ALSA-2026:86203
AlmaLinux:9go-toolset1.26.10-1.el9_8ALSA-2026:86196
AlmaLinux:10golang1.26.10-1.el10_2.alma.1ALSA-2026:86093
AlmaLinux:8golang1.26.10-1.module_el8.10.0+4307+6e4cbc60ALSA-2026:86203
AlmaLinux:9golang1.26.10-1.el9_8ALSA-2026:86196
AlmaLinux:10golang-bin1.26.10-1.el10_2.alma.1ALSA-2026:86093
AlmaLinux:8golang-bin1.26.10-1.module_el8.10.0+4307+6e4cbc60ALSA-2026:86203
AlmaLinux:9golang-bin1.26.10-1.el9_8ALSA-2026:86196
AlmaLinux:10golang-docs1.26.10-1.el10_2.alma.1ALSA-2026:86093
AlmaLinux:8golang-docs1.26.10-1.module_el8.10.0+4307+6e4cbc60ALSA-2026:86203
AlmaLinux:9golang-docs1.26.10-1.el9_8ALSA-2026:86196
AlmaLinux:10golang-misc1.26.10-1.el10_2.alma.1ALSA-2026:86093
AlmaLinux:8golang-misc1.26.10-1.module_el8.10.0+4307+6e4cbc60ALSA-2026:86203
AlmaLinux:9golang-misc1.26.10-1.el9_8ALSA-2026:86196
AlmaLinux:10golang-race1.26.10-1.el10_2.alma.1ALSA-2026:86093
AlmaLinux:8golang-race1.26.10-1.module_el8.10.0+4307+6e4cbc60ALSA-2026:86203
AlmaLinux:9golang-race1.26.10-1.el9_8ALSA-2026:86196
AlmaLinux:10golang-src1.26.10-1.el10_2.alma.1ALSA-2026:86093
AlmaLinux:8golang-src1.26.10-1.module_el8.10.0+4307+6e4cbc60ALSA-2026:86203
AlmaLinux:9golang-src1.26.10-1.el9_8ALSA-2026:86196
AlmaLinux:10golang-tests1.26.10-1.el10_2.alma.1ALSA-2026:86093
AlmaLinux:8golang-tests1.26.10-1.module_el8.10.0+4307+6e4cbc60ALSA-2026:86203
AlmaLinux:9golang-tests1.26.10-1.el9_8ALSA-2026:86196
AlmaLinux:8grafana9.2.10-36.el8_10ALSA-2026:88188
AlmaLinux:9grafana10.2.6-23.el9_8.7ALSA-2026:89744
AlmaLinux:10grafana-pcp5.3.0-8.el10_2.2ALSA-2026:88316
AlmaLinux:8grafana-pcp5.1.1-19.el8_10ALSA-2026:88189
AlmaLinux:9grafana-pcp5.1.1-17.el9_8.2ALSA-2026:88354
AlmaLinux:8grafana-selinux9.2.10-36.el8_10ALSA-2026:88188
AlmaLinux:9grafana-selinux10.2.6-23.el9_8.7ALSA-2026:89744
AlmaLinux:10ipp-usb0.9.27-7.el10_2.4ALSA-2026:88280
AlmaLinux:10opentelemetry-collector0.158.0-2.el10_2ALSA-2026:93596
AlmaLinux:9opentelemetry-collector0.158.0-2.el9_8ALSA-2026:93617
AlmaLinux:10podman7:5.8.2-11.el10_2.alma.1ALSA-2026:88336
AlmaLinux:10podman-docker7:5.8.2-11.el10_2.alma.1ALSA-2026:88336
AlmaLinux:10podman-remote7:5.8.2-11.el10_2.alma.1ALSA-2026:88336
AlmaLinux:10podman-tests7:5.8.2-11.el10_2.alma.1ALSA-2026:88336
AlmaLinux:10yggdrasil0.4.9.2-1.el10_2.4ALSA-2026:91138
AlmaLinux:10yggdrasil-devel0.4.9.2-1.el10_2.4ALSA-2026:91138
Alpine:v3.24docker29.9.0-r0ALPINE-CVE-2026-78669
Alpine:v3.24go1.26.9-r0ALPINE-CVE-2026-78669
Debian:12golang-1.19no fix listedDEBIAN-CVE-2026-78669
Debian:13golang-1.24no fix listedDEBIAN-CVE-2026-78669
Debian:14golang-1.261.26.9-1DEBIAN-CVE-2026-78669
Debian:14golang-1.271.27.2-1DEBIAN-CVE-2026-78669
Debian:12golang-golang-x-netno fix listedDEBIAN-CVE-2026-78669
Debian:13golang-golang-x-netno fix listedDEBIAN-CVE-2026-78669
Debian:14golang-golang-x-net1:0.60.0-1DEBIAN-CVE-2026-78669
Gogolang.org/x/net0.60.0GO-2026-6611
Gostdlib1.27.2GO-2026-6611
Gostdlib1.26.9GO-2026-6611
Rocky Linux:10buildah2:1.43.1-7.el10_2RLSA-2026:88262
Rocky Linux:10delve0:1.26.1-3.el10_2RLSA-2026:95519
Rocky Linux:8delve0:1.26.1-1.module+el8.10.0+40244+e7cb3ff8RLSA-2026:86203
Rocky Linux:10golang0:1.26.10-1.el10_2RLSA-2026:86093
Rocky Linux:9golang0:1.26.10-1.el9_8RLSA-2026:86196
Rocky Linux:10golang-github-openprinting-ipp-usb0:0.9.27-7.el10_2.4RLSA-2026:88280
Rocky Linux:8grafana0:9.2.10-36.el8_10RLSA-2026:88188
Rocky Linux:9grafana0:10.2.6-23.el9_8.7RLSA-2026:89744
Rocky Linux:10grafana-pcp0:5.3.0-8.el10_2.2RLSA-2026:88316
Rocky Linux:8grafana-pcp0:5.1.1-19.el8_10RLSA-2026:88189
Rocky Linux:9grafana-pcp0:5.1.1-17.el9_8.2RLSA-2026:88354
Rocky Linux:10opentelemetry-collector0:0.158.0-2.el10_2RLSA-2026:93596
Rocky Linux:9opentelemetry-collector0:0.158.0-2.el9_8RLSA-2026:93617
Rocky Linux:10podman7:5.8.2-11.el10_2RLSA-2026:88336
Rocky Linux:10yggdrasil0:0.4.9.2-1.el10_2.4RLSA-2026:91138
Ubuntu:22.04:LTSadsysno fix listedUBUNTU-CVE-2026-78669
Ubuntu:24.04:LTSadsysno fix listedUBUNTU-CVE-2026-78669
Ubuntu:26.04:LTSadsysno fix listedUBUNTU-CVE-2026-78669
Ubuntu:26.10adsysno fix listedUBUNTU-CVE-2026-78669
Ubuntu:22.04:LTScontainerdno fix listedUBUNTU-CVE-2026-78669
Ubuntu:26.10containerdno fix listedUBUNTU-CVE-2026-78669
Ubuntu:22.04:LTSgolang-1.17no fix listedUBUNTU-CVE-2026-78669
Ubuntu:22.04:LTSgolang-1.18no fix listedUBUNTU-CVE-2026-78669
Ubuntu:22.04:LTSgolang-1.20no fix listedUBUNTU-CVE-2026-78669
Ubuntu:22.04:LTSgolang-1.21no fix listedUBUNTU-CVE-2026-78669
Ubuntu:24.04:LTSgolang-1.21no fix listedUBUNTU-CVE-2026-78669
Ubuntu:22.04:LTSgolang-1.221.22.2-2~22.04.4USN-8935-1
Ubuntu:22.04:LTSgolang-1.221.22.2-2~22.04.4UBUNTU-CVE-2026-78669
Ubuntu:24.04:LTSgolang-1.221.22.2-2ubuntu0.5UBUNTU-CVE-2026-78669
Ubuntu:24.04:LTSgolang-1.221.22.2-2ubuntu0.5USN-8935-1
Ubuntu:22.04:LTSgolang-1.23no fix listedUBUNTU-CVE-2026-78669
Ubuntu:24.04:LTSgolang-1.23no fix listedUBUNTU-CVE-2026-78669
Ubuntu:26.04:LTSgolang-1.23no fix listedUBUNTU-CVE-2026-78669
Ubuntu:22.04:LTSgolang-1.24no fix listedUBUNTU-CVE-2026-78669
Ubuntu:24.04:LTSgolang-1.24no fix listedUBUNTU-CVE-2026-78669
Ubuntu:26.04:LTSgolang-1.24no fix listedUBUNTU-CVE-2026-78669
Ubuntu:22.04:LTSgolang-1.25no fix listedUBUNTU-CVE-2026-78669
Ubuntu:24.04:LTSgolang-1.25no fix listedUBUNTU-CVE-2026-78669
Ubuntu:26.04:LTSgolang-1.25no fix listedUBUNTU-CVE-2026-78669
Ubuntu:22.04:LTSgolang-1.26no fix listedUBUNTU-CVE-2026-78669
Ubuntu:24.04:LTSgolang-1.26no fix listedUBUNTU-CVE-2026-78669
Ubuntu:26.04:LTSgolang-1.26no fix listedUBUNTU-CVE-2026-78669
Ubuntu:26.10golang-1.26no fix listedUBUNTU-CVE-2026-78669
Ubuntu:26.10golang-1.27no fix listedUBUNTU-CVE-2026-78669
Ubuntu:22.04:LTSgolang-golang-x-netno fix listedUBUNTU-CVE-2026-78669
Ubuntu:26.04:LTSgolang-golang-x-netno fix listedUBUNTU-CVE-2026-78669
Ubuntu:26.10golang-golang-x-netno fix listedUBUNTU-CVE-2026-78669
Ubuntu:22.04:LTSgoogle-guest-agentno fix listedUBUNTU-CVE-2026-78669
Ubuntu:24.04:LTSgoogle-guest-agentno fix listedUBUNTU-CVE-2026-78669
Ubuntu:26.04:LTSgoogle-guest-agentno fix listedUBUNTU-CVE-2026-78669
Ubuntu:26.10google-guest-agentno fix listedUBUNTU-CVE-2026-78669
Ubuntu:22.04:LTSgoogle-osconfig-agentno fix listedUBUNTU-CVE-2026-78669
Ubuntu:24.04:LTSgoogle-osconfig-agentno fix listedUBUNTU-CVE-2026-78669
Ubuntu:26.04:LTSgoogle-osconfig-agentno fix listedUBUNTU-CVE-2026-78669
Ubuntu:26.10google-osconfig-agentno fix listedUBUNTU-CVE-2026-78669

Affected products (as reported)

VendorProductVersions
Go standard library net/http 0 – before 1.26.9
Go standard library net/http/internal/http2 1.27.0-0 – before 1.27.2
golang.org/x/net golang.org/x/net/http2 0 – before 0.60.0

Weakness: CWE-405 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References