CVE-2026-81915: Concrete CMS below 9.5.3 does not perform an object-level authorization check when a Page Type was updated

Q: How do I fix CVE-2026-81915?

concrete cms: upgrade to 9.5.3. Exact commands for each OS are on this page.

Q: Is CVE-2026-81915 being exploited?

CVE-2026-81915 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-81915 affect?

CVE-2026-81915 affects concrete cms. Severity is medium (CVSS 5.3). Concrete CMS below 9.5.3 does not perform an object-level authorization check when a Page Type was updated. The Types::submit() dashboard controller loaded and saved the Page Type identified by a user-supplied ptID without calling canEditPa

Q: How urgent is CVE-2026-81915?

Priority 29/100. Remotely exploitable, no login, no user action

Routine

MEDIUM 5.3REMOTEUPGRADE

CVE-2026-81915 is a medium-severity flaw (CVSS 5.3) affecting concrete cms. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Concrete CMS below 9.5.3 does not perform an object-level authorization check when a Page Type was updated. The Types::submit() dashboard controller loaded and saved the Page Type identified by a user-supplied ptID without calling canEditPageType(), so a signed-in dashboard user permitted to edit one Page Type could modify the configuration of Page Types outside their assigned authorization boundary. The update_page_type token was validated but i

Why this priority

Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	5.3 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.3% (top 79%)
CISA exploited list	No
Weakness	CWE-639, CWE-862
Published	2026-09-11
Last modified	2026-09-24

Publisher (CNA): ConcreteCMS · Vendor: concretecms

Last updated 2026-09-24 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-09-11 20:19 UTCPublished CVE record published
2026-09-24 20:07 UTCUpdated Record last modified

concretecms concrete cms UPGRADE

Affected: < 9.5.3

Fixed in: 9.5.3

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to 9.5.3 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade concrete-cms

Note

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

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-2026-81915?

concrete cms: upgrade to 9.5.3. Exact commands for each OS are on this page.

Is CVE-2026-81915 being exploited?

CVE-2026-81915 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-2026-81915 affect?

CVE-2026-81915 affects concrete cms. Severity is medium (CVSS 5.3). Concrete CMS below 9.5.3 does not perform an object-level authorization check when a Page Type was updated. The Types::submit() dashboard controller loaded and saved the Page Type identified by a user-supplied ptID without calling canEditPa

How urgent is CVE-2026-81915?

Priority 29/100. Remotely exploitable, no login, no user action

Related CVEs

CVE-2026-18111 MEDIUM 6.1 UPGRADE Concrete CMS 9 before 9.5.3 was vulnerable to stored cross-site scripting (XSS) in the Feature, Feature Link,
CVE-2026-18117 MEDIUM 5.4 UPGRADE Concrete CMS 9.0.0 through 9.5.3 is vulnerable to stored XSS via the custom page alias name (customAliasName)
CVE-2026-68526 MEDIUM 4.3 UPGRADE Concrete CMS before 9.5.3 did not validate an anti-CSRF token in the Calendar event duplicate dialog controlle
CVE-2026-81912 MEDIUM 5.7 UPGRADE Concrete CMS before 9.5.3 is vulnerable to Cross-Site Request Forgery in the Move Multiple Groups feature
CVE-2026-81913 MEDIUM 6.1 UPGRADE Concrete CMS versions 9.5.0 through 9.5.2 are vulnerable to Open Redirect via the rcURL parameter

References

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