CVE-2026-55090

mediumpriority · track · 0EPSS 0.005 · 46 %ileUS
grimoire priorityP3 · Track
Exploitable?
—
no known exploitation
Likely / severe?
0.55% (46th) EPSS
CVSS 5.3 · medium
Is it mine?
1 products
Check your exposure
Who says so?
1 sources
osv

EPSS · scored 2026-10-27

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.

01

cvss

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

5.3
010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · low–medium · 1.3–5.3

v4.05.3mediumCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:Xsecondary · security-advisories@github.com
v4.01.3lowCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:U/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:Xsecondary · CVSS-BT (t0sche)
02

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: none · Automatable: yes · Technical Impact: partialcoordinatorcisa_ssvcUS
03

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-79USCWE-79US
04

affected products (1)

Products and version ranges known to be affected.

05

advisories (1)

Vendor and ecosystem advisories describing this.

  • GHSA-2jp7-wwpg-3p9wEtherpad has stored XSS in HTML export via unescaped attribute-pool values2026-08-17ghsa · osvUS

    Fix: PR #7905 (ether/etherpad). `getHTMLFromAtext` in `src/node/utils/ExportHtml.ts` interpolates values from the `exportHtmlAdditionalTagsWithData` plugin hook into `span data-<k>="<v>"` without HTML-attribute escaping. The value comes verbatim from the pad attribute pool, which a pad editor controls via a crafted changeset (only `author` attributes are validated; `moveOpsToNewPool` -> `AttributePool.putAttrib` stores any value). With a bundled plugin that registers the hook (ep_font_color / ep_font_size), an attribute value such as `" onload="alert(1)` is exported as `<span data-color="" onload="alert(1)">` and served as text/html, yielding stored XSS for any collaborator who opens the export. Fix: escape the name and value via `Security.escapeHTMLAttribute`. PR #7905 also adds a startup warning when default/placeholder account or SSO credentials are configured (defense-in-depth, non-breaking).

06

sources

Which sources assert this record, and when.

osvNVDCVE.orgMITRE
published 2026-08-19modified 2026-08-20
07

references (4) nvd

External citations — patches, advisories, analysis.

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