CVE-2021-28145

lowpriority · track · 22EPSS 0.009 · 58 %ileEUUS

grimoire priorityP3 · Track

Exploitable?

—

no known exploitation

Likely / severe?

0.86% (58th) EPSS

CVSS 3.5 · low

Is it mine?

3 products

Check your exposure

Who says so?

4 sources

cnnvd · enisa_euvd · nvd · osv

EPSS · scored 2026-10-28

Concrete CMS (formerly concrete5) before 8.5.5 allows remote authenticated users to conduct XSS attacks via a crafted survey block. This requires at least Editor privileges.

cvss

Technical severity, 0–10. One row per scoring source.

5.4

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · low–medium · 3.5–5.4

v2.03.5lowAV:N/AC:M/Au:S/C:N/I:P/A:Nprimary · NVD / NIST USexploitability 6.8 · impact 2.9

v3.15.4mediumCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:Nprimary · NVD / NIST USexploitability 2.3 · impact 2.7

v3.15.4mediumCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:Nsecondary · OSV

v3.15mediumCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N/E:Usecondary · CVSS-BT (t0sche)

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-79USprimaryCWE-79US

affected products (3)

Products and version ranges known to be affected.

n/a n/a≤ n/aenisa_euvdEU
concretecms concrete cms< 8.5.5nvdUScpe:2.3:a:concretecms:concrete_cms:*:*:*:*:*:*:*:*
Packagist concrete5/concrete5< 8.5.5osvUSpkg:composer/concrete5/concrete5

advisories (1)

Vendor and ecosystem advisories describing this.

GHSA-7388-7vq2-m4f4Concrete CMS Cross-site Scripting via Survey Blocks2022-05-24ghsa · osvUS
Concrete CMS (formerly concrete5) before 8.5.5 allows remote authenticated users to conduct Cross-site Scripting (XSS) attacks via a crafted survey block. This requires at least Editor privileges.

also known as (3)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd nvd osv NVD CVE.org MITRE

published 2021-03-18modified 2026-06-17

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+53061 more

references (7)

External citations — patches, advisories, analysis.

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