Etherpad: JWT `admin` claim presence-only check lets non-admin OAuth users invoke every Etherpad HTTP API endpoint (CVE-2026-55089) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-55089

Etherpad: JWT `admin` claim presence-only check lets non-admin OAuth users invoke every Etherpad HTTP API endpoint

Answer in brief

CVE-2026-55089 records a Unknown severity vulnerability in Etherpad: JWT `admin` claim presence-only check lets non-admin OAuth users invoke every Etherpad HTTP API endpoint. The current sources do not mark it as known exploited. The current feed maps ether/etherpad (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Aug 19, 2026Updated Aug 19, 2026Source checked Aug 19, 2026First seen by HOL Aug 19, 2026Material review Aug 19, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Not reported

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps ether/etherpad (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
ether/etherpadgeneric	>= 2.1.0, < 3.1.0	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for ether/etherpad.
Review the reported fix. Monitor this advisory for an available fix and review any installs of the affected package.

Evidence timeline and material changes

Published upstream
Aug 19, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Aug 19, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Aug 19, 2026

Sources and claim methodology

Upstream source description

Etherpad is a real-time collaborative editor. From 2.1.0 until 3.1.0, Etherpad's src/node/handler/APIHandler.ts authorizes requests to /api/2/* in the authorization_code OAuth path by using requiredClaims with the admin claim. This check requires only that the claim exists, while src/node/security/OAuth2Provider.ts issues admin: false for configured non-admin users. A non-admin user with a valid signed token can therefore invoke administrative functions including setHTML, setText, appendText, deletePad, copyPad, movePad, restoreRevision, anonymizeAuthor, listAllPads, and listAuthorsOfPad, allowing disclosure, modification, or deletion of pads across the instance. This issue is fixed in version 3.1.0.

Quoted source text, attributed separately from HOL analysis.