CVE-2026-55086
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.
What this means for your business
- An attacker can use it only with access to the machine itself, with an ordinary user login, and without anyone at your company clicking anything.
- FIRST's prediction model gives it a 0.2% chance of attack attempts being seen in the next 30 days, ranking above 7% of all known flaws.
What to do
- 1Ask your IT team or provider whether any of your systems use the affected product.
- 2If you do, follow the vendor's guidance. No patch reference has been published yet.
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Scoring
- CVSS
- 4.2 (v3.1)
- Vector
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:L/I:L/A:N- Weakness
- CWE-59
- Assigned by
- security-advisories@github.com
Dates
- Published
- 2026-08-19
- Last modified
- 2026-09-09
- Sources
- NVD
References
- https://github.com/ether/etherpad/commit/8c6104c5d5daf41f0d454acc04d42dffa0e0d996
- https://github.com/ether/etherpad/pull/7784
- https://github.com/ether/etherpad/releases/tag/v3.1.0
- https://github.com/ether/etherpad/security/advisories/GHSA-2jwf-f4xq-f24h
- https://github.com/ether/etherpad/security/advisories/GHSA-2jwf-f4xq-f24h