CVE-2026-56862: Handshake messages, such as KeyUpdate, are always considered as state-advancing, regardless of whether a hands

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HIGH 7.5REMOTE

CVE-2026-56862 is a high-severity flaw (CVSS 7.5) affecting affected software. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Handshake messages, such as KeyUpdate, are always considered as state-advancing, regardless of whether a handshake has been completed or not. As a result, a malicious client can keep sending KeyUpdate messages to force the server to keep performing key derivation operations indefinitely.

Why this priority

High severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.6% (top 54%)
CISA exploited list	No
Weakness	CWE-770
Published	2026-08-13
Last modified	2026-10-24

Publisher (CNA): Go Project

Last updated 2026-10-24 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Timeline

2026-08-13 22:17 UTCPublished CVE record published
2026-10-24 16:10 UTCUpdated Record last modified

Exact fixes by distribution

Fedora 46 · sugar-clock · FIXED · 22.1-17.fc46 · FEDORA-2026-57948849df · source

sudo dnf upgrade --advisory=FEDORA-2026-57948849df

Fedora ELN · selinux-policy · FIXED · 45.23-1.eln159 · FEDORA-2026-3668c969a2 · source

sudo dnf upgrade --advisory=FEDORA-2026-3668c969a2

Ubuntu 20.04 · golang-1.22 · FIXED · 1.22.2-2~20.04.3

sudo apt update && sudo apt install --only-upgrade golang-1.22 dpkg --compare-versions "$(dpkg-query -W -f='${Version}' golang-1.22)" ge "1.22.2-2~20.04.3" && echo PATCHED || echo STILL-VULNERABLE

Ubuntu 22.04 · golang-1.22 · FIXED · 1.22.2-2~22.04.4

sudo apt update && sudo apt install --only-upgrade golang-1.22 dpkg --compare-versions "$(dpkg-query -W -f='${Version}' golang-1.22)" ge "1.22.2-2~22.04.4" && echo PATCHED || echo STILL-VULNERABLE

Ubuntu 24.04 · golang-1.22 · FIXED · 1.22.2-2ubuntu0.5

sudo apt update && sudo apt install --only-upgrade golang-1.22 dpkg --compare-versions "$(dpkg-query -W -f='${Version}' golang-1.22)" ge "1.22.2-2ubuntu0.5" && echo PATCHED || echo STILL-VULNERABLE

Debian 12 · golang-1.19 · NO FIX YET

Debian 13 · golang-1.24 · NO FIX YET

RHEL 10 · golang · FIXED · golang-1.26.7-1.el10_2

sudo dnf upgrade --advisory=RHSA-2026:60306 rpm -q golang

RHEL 10 · go-fdo-client · FIXED · go-fdo-client-1.0.0-4.el10_2.7

sudo dnf upgrade --advisory=RHSA-2026:62577 rpm -q go-fdo-client

RHEL 10 · go-fdo-server · FIXED · go-fdo-server-1.0.1-2.el10_2.4

sudo dnf upgrade --advisory=RHSA-2026:62578 rpm -q go-fdo-server

RHEL 10 · golang-github-openprinting-ipp-usb · FIXED · golang-github-openprinting-ipp-usb-0.9.27-7.el10_2.3

sudo dnf upgrade --advisory=RHSA-2026:62631 rpm -q golang-github-openprinting-ipp-usb

RHEL 10 · grafana · FIXED · grafana-10.2.6-28.el10_2.5

sudo dnf upgrade --advisory=RHSA-2026:63022 rpm -q grafana

Alpine 3.24 · go · FIXED · go-1.26.8-r0

apk add --upgrade go apk info -v go

Amazon Linux 2023 · see advisory · FIXED · ALAS2023-2026-2114 · source

sudo dnf update --advisory=ALAS2023-2026-2114

Amazon Linux 2 · see advisory · FIXED · ALAS2-2026-3893 · source

sudo yum update --advisory=ALAS2-2026-3893

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-56862?

No fixed release is listed yet. Watch the vendor advisory and apply any mitigation shown on this page.

Is CVE-2026-56862 being exploited?

CVE-2026-56862 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-56862 affect?

CVE-2026-56862 affects affected software. Severity is high (CVSS 7.5). Handshake messages, such as KeyUpdate, are always considered as state-advancing, regardless of whether a handshake has been completed or not. As a result, a malicious client can keep sending KeyUpdate messages to force the server to keep pe

How urgent is CVE-2026-56862?

Priority 43/100. High severity; Remotely exploitable, no login, no user action

References

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