ep_etherpad-lite: Device-to-device author-token transfer endpoint is replayable, never expires, and exposes the cleartext author token

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

6.8 · CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N

EPSS

• CVE-2026-55088: 0.44% estimated exploitation activity in the next 30 days; percentile 38.21 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Etherpad's device-to-device author-token transfer endpoint is replayable, never expires, and exposes the cleartext author token in the GET response body Description Etherpad ships an endpoint pair under /tokenTransfer (src/node/hooks/express/tokenTransfer.ts) that lets a logged-in user move their HttpOnly author token to a different browser (typically by scanning a QR code containing the transfer URL). The flow is: 1. POST /tokenTransfer — the source device sends a request whose own author cookie is read off the server-side cookie jar. The server mints a random UUID and stores the author token (and arbitrary prefsHttp field) under a DB key keyed by that UUID. The UUID is returned. 2. GET /tokenTransfer/{uuid} — the destination device GETs the URL containing the UUID. The server reads the stored record and sets the HttpOnly author cookie on the response. The original implementation has three serious flaws: 1. No expiration check. createdAt is written to the record on POST but never…

Published by the source

13 Aug 2026, 14:12 UTC

Last modified by the source

13 Aug 2026, 14:13 UTC

Source last checked

26 Oct 2026, 13:01 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-vqfp-p66c-xrp9

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# Patch Next advisory brief: CVE-2026-55088

Advisory: ep_etherpad-lite: Device-to-device author-token transfer endpoint is replayable, never expires, and exposes the cleartext author token
IDs: CVE-2026-55088, GHSA-vqfp-p66c-xrp9
Record: https://patchnext.com/advisories/cve-2026-55088 (revision 1, source checked 26 Oct 2026, 13:01 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.8)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: ep_etherpad-lite 3.1.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm ep_etherpad-lite: affected >= 2.6.0, <= 3.0.0; fixed in 3.1.0

## Suggested inspection (read-only)
- `npm ls ep_etherpad-lite --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on ep_etherpad-lite.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-vqfp-p66c-xrp9 (GitHub-reviewed advisory GHSA-vqfp-p66c-xrp9 lists affected ranges: npm ep_etherpad-lite >=2.6.0 <=3.0.0)

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