CVE-2026-55090
Published:August 19, 2026
Updated:September 24, 2026
Etherpad is a real-time collaborative editor. Prior to 3.3.0, getHTMLFromAtext in src/node/utils/ExportHtml.ts interpolates values from the exportHtmlAdditionalTagsWithData plugin hook into span data attributes without HTML attribute escaping. A pad editor can place an attacker-controlled value into the attribute pool through moveOpsToNewPool and AttributePool.putAttrib. When a bundled plugin such as ep_font_color or ep_font_size registers the hook, opening the resulting HTML export causes the value to execute as stored cross-site scripting in the Etherpad origin. This issue is fixed in version 3.3.0.
Affected Packages
https://github.com/ether/etherpad.git (GITHUB):
Affected version(s) >=1.6.0 <3.3.0Fix Suggestion:
Update to version 3.3.0https://github.com/ether/etherpad.git (GITHUB):
Affected version(s) >=v1.9.0 <v3.3.0Fix Suggestion:
Update to version v3.3.0ep_etherpad-lite (NPM):
Affected version(s) =1.8.14 <3.3.0Fix Suggestion:
Update to version 3.3.0Related Resources (8)
Do you need more information?
Contact UsCVSS v4
Base Score:
5.3
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
PASSIVE
Vulnerable System Confidentiality
NONE
Vulnerable System Integrity
NONE
Vulnerable System Availability
NONE
Subsequent System Confidentiality
LOW
Subsequent System Integrity
LOW
Subsequent System Availability
NONE
CVSS v3
Base Score:
6.1
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
REQUIRED
Scope
CHANGED
Confidentiality
LOW
Integrity
LOW
Availability
NONE
Weakness Type (CWE)
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
EPSS
Base Score:
0.41