CVE-2026-55088 ep_etherpad-lite: Device-to-device author-token transfer endpoint is replayable, never expires, and exposes the cleartext author token
Unauthenticated attackers can replay token transfer requests to steal cleartext author tokens and impersonate users in Etherpad.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-55088?
CVE-2026-55088 is a medium-severity vulnerability in etherpad, published on 19 Aug 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
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.
Which versions are affected by CVE-2026-55088?
2 open source packages ship an affected version, including ep_etherpad-lite.
| Package | Affected | Fixed in |
|---|---|---|
ep_etherpad-lite npm | From 2.6.0 | 3.1.0 |
ep_etherpad-lite npm | From 2.6.0 | 3.1.0 |
How do I fix CVE-2026-55088?
Upgrade ep_etherpad-lite to 3.1.0 or later.
Is CVE-2026-55088 being exploited?
There is no known exploitation of CVE-2026-55088 in the wild and no public exploit code.
Sources
Also known as GHSA-vqfp-p66c-xrp9.