CVE-2026-55085Critical· 9.6▾ Midnight

Etherpad is a real-time collaborative editor

▾ Midnight zone — Critical, or high with PoC / in-the-wild

Depth score53/ 100 · Moderate

impact 52.8 · likelihood 0.1 · exploitation 0

⚡ Agent-ready:Raw markdown ↗JSON ↗

Proof of concept

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Published

Aug 19, 2026

Updated

Sep 9, 2026

CVSS

9.6

Vendor

—

Product

—

CWE

CWE-79

Depth score

53 · Moderate

EPSS

0.45% · p39

Platforms

—

Source

NVD

Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:L

EPSS history

Exploit-prediction probability, daily snapshots since Sep 9.

0.4% → 0.5%▲ 0.09%

Timeline

Disclosure to exploitation, from the record and what we observed since indexing it.

4 events · 23 days

Aug 19, 2026Published
Disclosed via NVD
Sep 9, 2026Record revised
Last analysed / modified upstream
Sep 9, 2026EPSS first tracked
0.4%
Sep 11, 2026EPSS peak
0.4% → 0.5%

CWE-79 #nvd

Full technical detail▾

Overview

Etherpad is a real-time collaborative editor. Prior to 3.3.1, result.appendSpan in src/static/js/domline.ts interpolates the start attribute of a numbered list directly into an unquoted ol start attribute before assigning the generated markup to node.innerHTML. ImportEtherpad.setPadRaw in src/node/utils/ImportEtherpad.ts accepts attacker-controlled attribute-pool values from a crafted .etherpad import, including list:number1 and a malicious start value. Any user with write access to a pad can store markup that executes as cross-site scripting when another user opens the pad or /timeslider, including when an administrator views the pad. This issue is fixed in version 3.3.1.

Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

References

Related vulnerabilities

Connected by shared product, vendor, weakness, or advisory.

#nvd

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