NIST deprecates RSA-2048 from 2030. Find every one of them before attackers do.
🐘
🐘 Packagist
Not in CISA KEV
MEDIUM severity

Concrete CMS stored XSS vulnerability in the "Top Navigator Bar" blockGHSA-998c-q8hh-h8gv

MEDIUMFix: concretecms/concretecms#12128

GHSA-998c-q8hh-h8gv is a medium-severity (CVSS 4.8) Cross-site Scripting (XSS) vulnerability in concrete5/concrete5. A fix is available for concrete5/concrete5 — see the affected versions and patch details below.

Also known asCVE-2024-8660
Published
Updated
Affected
1 pkg
Patched
1 / 1
Exploits
None indexed
Exploitation data as of Nov 6, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

  • CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for GHSA-998c-q8hh-h8gv.

EPSS Exploitation Probability

via FIRST.org ↗
0.3%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs22th percentile — riskier than 22% of all scored CVEsHighest risk
0.00%0.27%0.54%0.81%0.3%0.3%May 26Sep 26Nov 26

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

1 pkg affected
🐘concrete5/concrete5

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.

Description

Concrete CMS versions 9.0.0 through 9.3.3 are affected by a stored XSS vulnerability in the "Top Navigator Bar" block. Since the "Top Navigator Bar" output was not sufficiently sanitized, a rogue administrator could add a malicious payload that could be executed when targeted users visited the home page.The Concrete CMS Security Team gave this vulnerability a CVSS v4 score of 4.6 with vector CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:A/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N https://www.first.org/cvss/calculator/4.0#CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:A/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N . This does not affect versions below 9.0.0 since they do not have the Top Navigator Bar Block. Thanks, Chu Quoc Khanh for reporting.

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
🐘Packagistconcrete5/concrete5≥ 9.0.0&&< 9.3.39.3.3composer require concrete5/concrete5:^9.3.3

Affected Products

1 product · 1 configurations
Application
concrete cmsconcretecms
≥ 9.0.0 && < 9.3.4
range

Detection & mitigation playbook

Open-source dependency

  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for concrete5/concrete5, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

  2. Fix

    Update concrete5/concrete5 to 9.3.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-998c-q8hh-h8gv is resolved across your whole dependency graph.

  3. Workarounds

    Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.

Frequently Asked Questions

Concrete CMS versions 9.0.0 through 9.3.3 are affected by a stored XSS vulnerability in the "Top Navigator Bar" block. Since the "Top Navigator Bar" output was not sufficiently sanitized, a rogue administrator could add a malicious payload that could be executed when targeted users visited the home page. This does not affect versions below 9.0.0 since they do not have the Top Navigator Bar Block. Thanks, Chu Quoc Khanh for reporting.
O3 Security · Impact-Aware SCA

Is GHSA-998c-q8hh-h8gv in your dependencies?

Find it across Packagist, including transitive dependencies.

Scan my dependencies How O3 SCA works
Concrete CMS stored XSS vulnerability in the "Top…