Concrete CMS vulnerabilities: known CVEs & security history
Concrete CMS · CMS · 44 tracked CVEs · 0 actively exploited · updated August 2026 · what is a CVE? →
This is the full list of known vulnerabilities (CVEs) across all Concrete CMS release lines — 44 in total. A CVE here doesn't mean your version is affected — check Concrete CMS's current status and the safe version to run.
Known Concrete CMS CVEs
Actively-exploited and most-severe first. Open any CVE for full details.
| CVE | Severity | CVSS | EPSS | Year |
|---|---|---|---|---|
| CVE-2026-8434 | high | 8.8 | 0% | 2026 |
| CVE-2026-8433 | high | 8.8 | 0% | 2026 |
| CVE-2026-8432 | high | 8.8 | 0% | 2026 |
| CVE-2026-8427 | high | 8.8 | 0% | 2026 |
| CVE-2026-8416 | high | 8.8 | 0% | 2026 |
| CVE-2026-8415 | high | 8.8 | 0% | 2026 |
| CVE-2026-8414 | high | 8.8 | 0% | 2026 |
| CVE-2026-8413 | high | 8.8 | 0% | 2026 |
| CVE-2026-8412 | high | 8.8 | 0% | 2026 |
| CVE-2026-8411 | high | 8.8 | 0% | 2026 |
| CVE-2026-8410 | high | 8.8 | 0% | 2026 |
| CVE-2026-8409 | high | 8.8 | 0% | 2026 |
| CVE-2026-8428 | high | 8.8 | 0% | 2026 |
| CVE-2026-8426 | high | 8.8 | 0% | 2026 |
| CVE-2026-8421 | high | 8.8 | 0% | 2026 |
| CVE-2026-8417 | high | 8.8 | 0% | 2026 |
| CVE-2026-8350 | high | 8.8 | 0% | 2026 |
| CVE-2026-8135 | high | 7.2 | 0% | 2026 |
| CVE-2026-8134 | high | 7.2 | 1% | 2026 |
| CVE-2026-8435 | medium | 6.5 | 0% | 2026 |
| CVE-2026-8140 | medium | 6.5 | 0% | 2026 |
| CVE-2026-7890 | medium | 6.4 | 0% | 2026 |
| CVE-2026-7887 | medium | 6.4 | 0% | 2026 |
| CVE-2026-8245 | medium | 5.4 | 0% | 2026 |
| CVE-2026-8139 | medium | 5.4 | 0% | 2026 |
| CVE-2026-8203 | medium | 5.4 | 0% | 2026 |
| CVE-2026-8337 | medium | 5.3 | 0% | 2026 |
| CVE-2026-8240 | medium | 5.3 | 0% | 2026 |
| CVE-2026-8239 | medium | 5.3 | 0% | 2026 |
| CVE-2026-8238 | medium | 5.3 | 0% | 2026 |
| CVE-2026-8237 | medium | 5.3 | 0% | 2026 |
| CVE-2026-7879 | medium | 5.3 | 0% | 2026 |
| CVE-2026-8205 | medium | 5.3 | 0% | 2026 |
| CVE-2026-8204 | medium | 5.3 | 0% | 2026 |
| CVE-2026-6826 | medium | 5.3 | 0% | 2026 |
| CVE-2026-8353 | medium | 4.8 | 0% | 2026 |
| CVE-2026-8197 | medium | 4.8 | 0% | 2026 |
| CVE-2026-8347 | medium | 4.3 | 0% | 2026 |
| CVE-2026-8340 | medium | 4.3 | 0% | 2026 |
| CVE-2026-8327 | medium | 4.3 | 0% | 2026 |
| CVE-2026-8236 | medium | 4.3 | 0% | 2026 |
| CVE-2026-7886 | medium | 4.3 | 0% | 2026 |
| CVE-2026-7882 | medium | 4.3 | 0% | 2026 |
| CVE-2026-7881 | medium | 4.3 | 0% | 2026 |
Is my Concrete CMS version affected?
The list above spans every release. To know whether your version is affected — and the minimum safe version to upgrade to — check it directly.
Check your Concrete CMS version → · Monitor Concrete CMS for new CVEs →
Concrete CMS vulnerabilities — frequently asked
How many known vulnerabilities does Concrete CMS have?
IsItPatched tracks 44 CVEs for Concrete CMS. 0 are critical-severity and 19 high-severity. These span every release line — what matters is whether the version you run is affected.
Does Concrete CMS have any actively-exploited vulnerabilities?
None of Concrete CMS's tracked CVEs are currently in CISA's KEV catalog — but new ones can be added at any time, so keep your version current.
What is the most severe Concrete CMS vulnerability?
Among tracked issues, CVE-2026-8434 (HIGH, CVSS 8.8) ranks highest — a Cross-site request forgery (CSRF) weakness.
Is Concrete CMS safe to use?
It depends on the version. The latest supported Concrete CMS release (9.5.2) clears the known issues; older versions may still be affected. Check the exact version you run for a verdict.
CVE data aggregated from NVD, CISA KEV and EPSS (FIRST.org). Related: Concrete CMS security status · Concrete CMS end-of-life · actively-exploited CVEs. Always verify against Concrete CMS's advisories — see our disclaimer.