CVE-2026-55086Etherpad: Import/export use Math.random() for temp file paths; predictable paths on shared /tmp enable symlink-based file overwrite

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.

CVSS

4.2 MEDIUM (v3.1, CNA)CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:L/I:L/A:N

Weakness (CWE)

CWE-59, CWE-377

Known exploited

Not in CISA's KEV catalog

EPSS (exploitation in the next 30 days)

Not loaded for this CVE

Assigned by

GitHub_M

NVD analysis

Deferred

Record last updated

Aug 25, 2026

First seen by InfoSec Signals

Oct 9, 2026

The CVE record on cve.org · NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.