CVE-2026-33159: Craft CMS is a content management system (CMS)

Routine

MEDIUM 6.5REMOTEUPGRADE

CVE-2026-33159 is a medium-severity flaw (CVSS 6.5) affecting craft cms. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Craft CMS is a content management system (CMS). From version 4.0.0-RC1 to before version 4.17.8 and from version 5.0.0-RC1 to before version 5.9.14, guest users can access Config Sync updater index, obtain signed data, and execute state-changing Config Sync actions (regenerate-yaml, apply-yaml-changes) without authentication. This issue has been patched in versions 4.17.8 and 5.9.14.

Why this priority

Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	6.5 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.3% (top 76%)
CISA exploited list	No
Weakness	CWE-306, CWE-862
Published	2026-03-24
Last modified	2026-06-17

Publisher (CNA): GitHub, Inc. · Vendor: craftcms

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

Am I affected?

Timeline

2026-03-24 18:16 UTCPublished CVE record published
2026-06-17 10:37 UTCUpdated Record last modified

craftcms craft cms UPGRADE

Affected: > 4.0.0 and < 4.17.8 · > 5.0.0 and < 5.9.14 · 4.0.0 · 4.0.0 rc1 · 4.0.0 rc2 · 4.0.0 rc3 · 5.0.0 · 5.0.0 rc1

Fixed in: 4.17.8, 5.9.14

Safe to downgrade to: a release before 4.0.0

1. Check installed version

apt-cache policy craft-cms || rpm -q craft-cms || craft-cms --version

2. UPGRADE to 4.17.8 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade craft-cms

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade craft-cms

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 4.0.0 (Debian / Ubuntu)

apt-cache madison craft-cms sudo apt install craft-cms=<VERSION_BEFORE_4.0.0> sudo apt-mark hold craft-cms

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

dnf --showduplicates list craft-cms sudo dnf downgrade craft-cms-<VERSION_BEFORE_4.0.0> sudo dnf versionlock add craft-cms

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.

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-2026-33159?

craft cms: upgrade to 4.17.8, 5.9.14. Exact commands for each OS are on this page.

Is CVE-2026-33159 being exploited?

CVE-2026-33159 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-2026-33159 affect?

CVE-2026-33159 affects craft cms. Severity is medium (CVSS 6.5). Craft CMS is a content management system (CMS). From version 4.0.0-RC1 to before version 4.17.8 and from version 5.0.0-RC1 to before version 5.9.14, guest users can access Config Sync updater index, obtain signed data, and execute state-cha

How urgent is CVE-2026-33159?

Priority 34/100. Remotely exploitable, no login, no user action

Related CVEs

CVE-2026-33162 MEDIUM 6.5 UPGRADE Craft CMS is a content management system (CMS)
CVE-2026-33161 MEDIUM 4.3 UPGRADE Craft CMS is a content management system (CMS)
CVE-2026-33160 MEDIUM 5.3 UPGRADE Craft CMS is a content management system (CMS)
CVE-2026-33158 MEDIUM 6.5 UPGRADE Craft CMS is a content management system (CMS)
CVE-2026-33157 HIGH 7.2 UPGRADE Craft CMS is a content management system (CMS)

References

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