CVE-2025-27802Public exploitNetwork attack vector

Stored script execution via reverted RTE encoding

Published Jul 28, 2025 · Updated Nov 3, 2025

Stored XSS in Optimizely Content Management System 11.x and 12.x allows remote authenticated users to execute script in preview users' browsers. The Edit section's frontend encodes HTML entered in an RTE property, but a WebEditor can intercept the contentdata request and revert that encoding before storage. Execution occurs when another user opens the published page preview, exposing that user's browser session to attacker-controlled JavaScript.

CVSS severity4.8
Medium
EPSS probability0.33%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stored XSS in Optimizely Content Management System 11.x and 12.x allows remote authenticated users to execute script in preview users' browsers. The Edit section's frontend encodes HTML entered in an RTE property, but a WebEditor can intercept the contentdata request and revert that encoding before storage. Execution occurs when another user opens the published page preview, exposing that user's browser session to attacker-controlled JavaScript.

The record

CVE
CVE-2025-27802
Published
Jul 28, 2025
Updated
Nov 3, 2025
Vendor
Optimizely
Product
Optimizely Content Management System (CMS)
Classifications
CWE-79, CAPEC-63, T1059.007
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 28, 2025CVE publishedPublication date reported by the CVE source.
  2. Nov 3, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=11.x <11.21.4
  2. Affected versionversion=12.x <12.22.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Optimizely · Optimizely Content Management System (CMS)version=11.x <11.21.4; version=12.x <12.22.1

Published CVSS scores

4.8SEC-VLabCVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:N/VI:L/VA:L/SC:L/SI:L/SA:N
4.8SEC-VLabCVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CAPEC-63Cross-Site Scripting (XSS)
T1059.007JavaScript/JScript

Public exploit references

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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