How severe is CVE-2021-40098?

CVE-2021-40098 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-40098 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (75th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-40098?

CVE-2021-40098 affects Concretecms Concrete Cms. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-40098?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2021-40098 published?

CVE-2021-40098 was published on 2021-09-27 and last updated on 2026-06-17.

CVE-2021-40098

CVE-2021-40098 is a critical-severity vulnerability in Concretecms Concrete Cms with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-22.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 7.5
EPSS exploit prediction: 2% (75th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-22
Affected product: Concretecms Concrete Cms
Published: 2021-09-27
Last modified: 2026-06-17

Description

An issue was discovered in Concrete CMS through 8.5.5. Path Traversal leading to RCE via external form by adding a regular expression.

Frequently asked questions

What is CVE-2021-40098?: An issue was discovered in Concrete CMS through 8.5.5. Path Traversal leading to RCE via external form by adding a regular expression.
How severe is CVE-2021-40098?: CVE-2021-40098 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-40098 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (75th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-40098?: CVE-2021-40098 affects Concretecms Concrete Cms. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-40098?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2021-40098 published?: CVE-2021-40098 was published on 2021-09-27 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:concretecms:concrete_cms:*:*:*:*:*:*:*:*

More vulnerabilities in Concretecms Concrete Cms

CVE-2023-48648 — Critical (CVSS 9.8): Concrete CMS before 8.5.13 and 9.x before 9.2.2 allows unauthorized access because directories can be created with…
CVE-2022-21829 — Critical (CVSS 9.8): Concrete CMS Versions 9.0.0 through 9.0.2 and 8.5.7 and below can download zip files over HTTP and execute code from…
CVE-2021-22958 — Critical (CVSS 9.8): A Server-Side Request Forgery vulnerability was found in concrete5 < 8.5.5 that allowed a decimal notation encoded IP…
CVE-2026-85385 — Critical (CVSS 9.6): Concrete CMS below 9.5.4 did not validate the user timezone value (uTimezone) on write and rendered it without output…
CVE-2022-30117 — Critical (CVSS 9.1): Concrete 8.5.7 and below as well as Concrete 9.0 through 9.0.2 allow traversal in /index.php/ccm/system/file/upload…
CVE-2021-40102 — Critical (CVSS 9.1): An issue was discovered in Concrete CMS through 8.5.5. Arbitrary File deletion can occur via PHAR deserialization in…

All CVEs affecting Concretecms Concrete Cms →

Other CWE-22 (Path Traversal) vulnerabilities

CVE-2026-55393 — Critical (CVSS 10.0): Unvalidated pathnames in the web interface in Teledyne FLIR Aware2 versions through 6.9.0.2 (PackBot) and 1.7.9…
CVE-2026-97163 — Critical (CVSS 10.0): Joomla Extension - lomart.fr - Unauthenticated remote code installation in UP plugin extension 5.0.0-5.2.0, 6.0.0-6.0.29
CVE-2026-80155 — Critical (CVSS 10.0): Lantronix SLC8000 before firmware v9.7.0.5, SLC9000 before firmware v9.7.0.2, EMG8500/EMG7500 before firmware v9.7.0.1,…
CVE-2026-70200 — Critical (CVSS 10.0): Improper limitation of a pathname to a restricted directory ('path traversal') in Azure Logic Apps allows an…
CVE-2026-85706 — Critical (CVSS 10.0): GitLab has remediated an issue in GitLab CE/EE affecting all versions from 18.7 before 18.11.12, 19.0 before 19.0.9,…
CVE-2026-76606 — Critical (CVSS 10.0): Joomla Extension - fabrikar.com - Path Traversal via image element in Fabrik < 4.7.2.

Browse all CWE-22 (Path Traversal) vulnerabilities →