Information disclosure in Ether Etherpad
CVE-2026-55088
Etherpad is a real-time collaborative editor. From 2.6.0 until 3.1.0, Etherpad's src/node/hooks/express/tokenTransfer.ts uses POST /tokenTransfer to store an author token for transfer between browsers and exposes it through GET /tokenTransfer/{uuid}. Although the record includes createdAt, the transfer has no expiration check, is not removed after successful redemption, and is returned by res.send(tokenData), including the raw author token. An unauthenticated attacker who obtains a transfer UUID can repeatedly redeem it, receive fresh author cookies, read the cleartext token, and impersonate the originating author for pad read and write operations. This issue is fixed in version 3.1.0.
Vulnerability class: Information Disclosure
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.8 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N.
EPSS exploit prediction
EPSS: 0.004 (35.9th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 36th percentile — 35.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: +0.001
Affected products
- Ether Etherpad — versions >= 2.6.0, < 3.1.0
Weakness classification (CWE)
References
Frequently asked questions
- What is CVE-2026-55088?
- CVE-2026-55088 is a medium-severity vulnerability in Ether Etherpad, classified under Information Disclosure. CVSS score: 6.8/10. Published 2026-08-19.
- How severe is CVE-2026-55088?
- Medium severity. CVSS v3 base score is 6.8 out of 10.