CVE-2021-39166Network attack vector

Authenticated XSS via unescaped preview text

Published Sep 1, 2021 · Updated Aug 4, 2024

Cross-site scripting in Pimcore before 10.1.2 allows remote authenticated users to execute script via object version previews. The preview renderer prints text-values without proper output escaping, allowing attacker-supplied markup or script to execute in the viewing user's browser. Access requires an authenticated account with resource permissions and user interaction with the preview; impact is browser-context script execution that can read or alter data available to that session.

CVSS severity8.0
High
EPSS probability0.78%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cross-site scripting in Pimcore before 10.1.2 allows remote authenticated users to execute script via object version previews. The preview renderer prints text-values without proper output escaping, allowing attacker-supplied markup or script to execute in the viewing user's browser. Access requires an authenticated account with resource permissions and user interaction with the preview; impact is browser-context script execution that can read or alter data available to that session.

The record

CVE
CVE-2021-39166
Published
Sep 1, 2021
Updated
Aug 4, 2024
Vendor
Pimcore
Product
Pimcore
Classifications
CWE-79, T1059.007
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 1, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 10.1.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Pimcore · Pimcoreversion=< 10.1.2

Published CVSS scores

8.0NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
3.5NVDAV:N/AC:M/Au:S/C:N/I:P/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1059.007Command and Scripting Interpreter: JavaScript

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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