CVE-2026-55086

Etherpad: Import/export use Math.random() for temp file paths; predictable paths on shared /tmp enable symlink-based file overwrite

Published Aug 19, 2026 CVSS 3.1 · 4.2 Medium EPSS < 1% KEV · Not listed
Description
Etherpad is a real-time collaborative editor. Prior to 3.1.0, src/node/handler/ImportHandler.ts and src/node/handler/ExportHandler.ts derive temporary filenames from Math.random() and place them in os.tmpdir(). On a host with a shared world-writable temporary directory, a local unprivileged attacker who predicts a filename can precreate a symbolic link to a file writable by the Etherpad process. Subsequent import or export operations can follow the link through fs.writeFile, fs.rename, or document-conversion output and overwrite the target with partially attacker-controlled content. This issue is fixed in version 3.1.0.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-2jwf-f4xq-f24h ep_etherpad-lite: Import/export uses Math.random() for temp file paths; predictable paths on shared /tmp enable symlink-based file overwrite
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Etherpad
Etherpad etherpad
Vendors & Products Etherpad
Etherpad etherpad
Type Values Removed Values Added
Description Etherpad is a real-time collaborative editor. Prior to 3.1.0, src/node/handler/ImportHandler.ts and src/node/handler/ExportHandler.ts derive temporary filenames from Math.random() and place them in os.tmpdir(). On a host with a shared world-writable temporary directory, a local unprivileged attacker who predicts a filename can precreate a symbolic link to a file writable by the Etherpad process. Subsequent import or export operations can follow the link through fs.writeFile, fs.rename, or document-conversion output and overwrite the target with partially attacker-controlled content. This issue is fixed in version 3.1.0.
Title Etherpad: Import/export use Math.random() for temp file paths; predictable paths on shared /tmp enable symlink-based file overwrite
Weaknesses CWE-377
CWE-59
References
Metrics cvssV3_1

{'score': 4.2, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:L/I:L/A:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Aug 25, 2026, 1:59 PM
Reserved
Jun 16, 2026, 2:41 PM
Status
Deferred
Published
Aug 19, 2026, 8:17 PM
Modified
Sep 9, 2026, 9:15 PM