Vulnerability · Published Aug 19, 2026 · Assigned by GitHub_M

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

Medium 4.2

In plain English

A medium-severity security flaw in etherpad from ether. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 3% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)4.2Medium

Exploit odds (30 days)0.1%top 96.7% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official 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.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
npm	ep_etherpad-lite	3.1.0	GHSA-2jwf-f4xq-f24h

Affected products (as reported)

Vendor	Product	Versions
ether	etherpad	< 3.1.0

Weakness: CWE-59, CWE-377 · Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:L/I:L/A:N

References

https://github.com/ether/etherpad/security/advisories/GHSA-2jwf-f4xq-f24h x_refsource_CONFIRM
https://github.com/ether/etherpad/pull/7784 x_refsource_MISC
https://github.com/ether/etherpad/commit/8c6104c5d5daf41f0d454acc04d42dffa0e0d996 x_refsource_MISC
https://github.com/ether/etherpad/releases/tag/v3.1.0 x_refsource_MISC