CVE-2025-68121: During session resumption in crypto/tls, if the underlying Config has its ClientCAs or RootCAs fields mutated

This week

CRITICAL 10.0REMOTEUPGRADE

CVE-2025-68121 is a critical-severity flaw (CVSS 10.0) affecting go. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

During session resumption in crypto/tls, if the underlying Config has its ClientCAs or RootCAs fields mutated between the initial handshake and the resumed handshake, the resumed handshake may succeed when it should have failed. This may happen when a user calls Config.Clone and mutates the returned Config, or uses Config.GetConfigForClient. This can cause a client to resume a session with a server that it would not have resumed with during the i

Why this priority

Critical severity
Public exploit reference
CISA SSVC: automatable with total technical impact
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	10.0 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.9% (top 40%)
CISA exploited list	No
Weakness	CWE-295
Published	2026-02-05
Last modified	2026-06-17

Publisher (CNA): Go Project · Vendor: golang

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-02-05 18:16 UTCPublished CVE record published
2026-06-17 09:58 UTCUpdated Record last modified

golang go UPGRADE

Affected: < 1.24.13 · >= 1.25.0 and < 1.25.7 · 1.26.0 rc1 · 1.26.0 rc2

Fixed in: 1.24.13, 1.25.7

Safe to downgrade to: a release before 1.25.0

1. Check installed version

apt-cache policy go || rpm -q go || go --version

2. UPGRADE to 1.24.13 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade go

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade go

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 1.25.0 (Debian / Ubuntu)

apt-cache madison go sudo apt install go=<VERSION_BEFORE_1.25.0> sudo apt-mark hold go

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list go sudo dnf downgrade go-<VERSION_BEFORE_1.25.0> sudo dnf versionlock add go

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Exact fixes by distribution

Fedora 46 · opensips · FIXED · 4.0.3-1.fc46 · FEDORA-2026-6700a0026c · source

sudo dnf upgrade --advisory=FEDORA-2026-6700a0026c

Fedora ELN · ibus-typing-booster · FIXED · 2.31.3-1.eln159 · FEDORA-2026-c895c68d60 · source

sudo dnf upgrade --advisory=FEDORA-2026-c895c68d60

Ubuntu 20.04 · golang-1.13 · NOT AFFECTED

Ubuntu 22.04 · golang-1.13 · NOT AFFECTED

Ubuntu 20.04 · golang-1.14 · NOT AFFECTED

Ubuntu 20.04 · golang-1.16 · NO FIX YET

Ubuntu 22.04 · golang-1.17 · NO FIX YET

Debian 12 · golang-1.19 · NO FIX YET

Debian 13 · golang-1.24 · NO FIX YET

RHEL 10 · golang · FIXED · golang-1.25.7-1.el10_1

sudo dnf upgrade --advisory=RHSA-2026:2706 rpm -q golang

RHEL 10 · grafana · FIXED · grafana-10.2.6-22.el10_1

sudo dnf upgrade --advisory=RHSA-2026:2914 rpm -q grafana

RHEL 10 · grafana-pcp · FIXED · grafana-pcp-5.3.0-2.el10_1

sudo dnf upgrade --advisory=RHSA-2026:3035 rpm -q grafana-pcp

RHEL 10 · golang-github-openprinting-ipp-usb · FIXED · golang-github-openprinting-ipp-usb-0.9.27-5.el10_1

sudo dnf upgrade --advisory=RHSA-2026:3092 rpm -q golang-github-openprinting-ipp-usb

RHEL 10 · buildah · FIXED · buildah-1.41.8-2.el10_1

sudo dnf upgrade --advisory=RHSA-2026:3297 rpm -q buildah

Alpine 3.22 · go · FIXED · go-1.24.12-r0

apk add --upgrade go apk info -v go

Alpine 3.23 · go · FIXED · go-1.25.6-r0

apk add --upgrade go apk info -v go

Amazon Linux 2023 · see advisory · FIXED · ALAS2023-2026-1473 · source

sudo dnf update --advisory=ALAS2023-2026-1473

Amazon Linux 2 · see advisory · FIXED · ALAS2-2026-3191 · source

sudo yum update --advisory=ALAS2-2026-3191

Advisories and coverage

Official advisories

CoreDNS Releases: v1.14.1 2026-01-16

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-2025-68121?

go: upgrade to 1.24.13, 1.25.7. Exact commands for each OS are on this page.

Is CVE-2025-68121 being exploited?

CVE-2025-68121 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-2025-68121 affect?

CVE-2025-68121 affects go. Severity is critical (CVSS 10.0). During session resumption in crypto/tls, if the underlying Config has its ClientCAs or RootCAs fields mutated between the initial handshake and the resumed handshake, the resumed handshake may succeed when it should have failed. This may ha

How urgent is CVE-2025-68121?

Priority 63/100. Critical severity; Public exploit reference; CISA SSVC: automatable with total technical impact; Remotely exploitable, no login, no user action

Software pages

Go (Golang) vulnerabilities

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References

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