Answer in brief
CVE-2026-54238 records a Low severity (CVSS 3.1) vulnerability in Supabase Realtime: Expired JWTs with string exp are accepted by REST broadcast authorization. The current sources do not mark it as known exploited. The current feed maps supabase/realtime (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 3.1. 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.
The current feed maps supabase/realtime (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| supabase/realtimegeneric | <2.103.1 | 2.103.1 |
Published upstream
Oct 22, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 22, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Oct 22, 2026
Supabase Realtime provides Broadcast, Presence, and Postgres Changes via WebSockets. Prior to version 2.103.1, the REST broadcast endpoints accept an expired JWT when the exp claim is encoded as a JSON string instead of a JSON number. The same route rejects an expired integer exp token signed with the same tenant secret. The accepted request returns 202 and emits the broadcast to subscribers. This could allow an unauthenticated attacker can broadcast realtime messages to subscribers. The attack can be performed via the Internet/only from within the supabase project. The impact of broadcasting messages to subscribers is application specific. This issue has been patched in version 2.103.1.
Quoted source text, attributed separately from HOL analysis.