How severe is CVE-2023-28820?

CVE-2023-28820 has a CVSS 3.x base score of 2.0, rated low severity. It is exploitable over network with high attack complexity, requires high privileges and user interaction. Impact on confidentiality is low, integrity none, and availability none.

Is CVE-2023-28820 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (31st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2023-28820?

CVE-2023-28820 affects Concretecms Concrete Cms. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2023-28820?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2023-28820 published?

CVE-2023-28820 was published on 2023-04-28 and last updated on 2026-06-17.

CVE-2023-28820

CVE-2023-28820 is a low-severity vulnerability in Concretecms Concrete Cms with a CVSS 3.x base score of 2.0. 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-79.

Key facts

Severity: Low (CVSS 3.x base score 2.0)
EPSS exploit prediction: 0% (31st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-79
Affected product: Concretecms Concrete Cms
Published: 2023-04-28
Last modified: 2026-06-17

Description

Concrete CMS (previously concrete5) before 9.1 is vulnerable to stored XSS in RSS Displayer via the href attribute because the link element input was not sanitized.

Frequently asked questions

What is CVE-2023-28820?: Concrete CMS (previously concrete5) before 9.1 is vulnerable to stored XSS in RSS Displayer via the href attribute because the link element input was not sanitized.
How severe is CVE-2023-28820?: CVE-2023-28820 has a CVSS 3.x base score of 2.0, rated low severity. It is exploitable over network with high attack complexity, requires high privileges and user interaction. Impact on confidentiality is low, integrity none, and availability none.
Is CVE-2023-28820 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (31st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-28820?: CVE-2023-28820 affects Concretecms Concrete Cms. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2023-28820?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2023-28820 published?: CVE-2023-28820 was published on 2023-04-28 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-2021-40098 — Critical (CVSS 9.8): An issue was discovered in Concrete CMS through 8.5.5. Path Traversal leading to RCE via external form by adding a…
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-79 (Cross-site Scripting (XSS)) vulnerabilities

CVE-2025-49410 — Critical (CVSS 10.0): Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in Imran Emu TC…
CVE-2024-47875 — Critical (CVSS 10.0): DOMPurify is a DOM-only, super-fast, uber-tolerant XSS sanitizer for HTML, MathML and SVG. DOMpurify was vulnerable to…
CVE-2024-6886 — Critical (CVSS 10.0): Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') vulnerability in Gitea…
CVE-2023-45144 — Critical (CVSS 10.0): com.xwiki.identity-oauth:identity-oauth-ui is a package to aid in building identity and service providers based on…
CVE-2023-45138 — Critical (CVSS 10.0): Change Request is an pplication allowing users to request changes on a wiki without publishing the changes directly.…
CVE-2022-4361 — Critical (CVSS 10.0): Keycloak, an open-source identity and access management solution, has a cross-site scripting (XSS) vulnerability in the…

Browse all CWE-79 (Cross-site Scripting (XSS)) vulnerabilities →