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Stream, proxy, WebSocket, and resource-boundary batch

Signal: The 2026-05-08 21:15 UTC advisory scan added boundary issues in event streams, telemetry exporters, cluster webhooks, agent WebSocket UIs, application SSRF, and long-poll body parsing.

Advisory cluster

  • eventsource-encoder SSE event injection — GHSA-m9g3-3g99-mhpx: eventsource-encoder <=1.0.1 let attacker-controlled event or id fields inject extra Server-Sent Events; patch to 1.0.2+.
  • OpenTelemetry.Exporter.Instana proxy TLS validation bypass — GHSA-wfr5-454p-mjc2: OpenTelemetry.Exporter.Instana <=1.0.7 bypassed certificate validation when a proxy was configured; patch to 1.1.0+.
  • Volcano admission webhook unbounded body DoS — GHSA-8wxp-xxp2-rcgx: volcano.sh/volcano webhook server accepted unbounded HTTP bodies; patch to 1.12.4+, 1.13.3+, or 1.14.2+.
  • Cline Kanban Server CSWSH — GHSA-5c57-rqjx-35g2: cline <=2.13.0 exposed a critical Cross-Origin WebSocket Hijacking path in the Kanban server; no patched version was listed at scan time.
  • monetr Lunch Flow SSRF — GHSA-29v9-frvh-c426: github.com/monetr/monetr <1.12.5 allowed server-side fetches during Lunch Flow link creation/refresh; patch to 1.12.5+.
  • Phoenix long-poll NDJSON allocation DoS — GHSA-628h-q48j-jr6q: phoenix >=1.7.0,<1.7.22 and >=1.8.0,<1.8.6 could allocate excessive memory while splitting long-poll NDJSON request bodies.

Why this matters

These are all “framing is authority” failures: an event field becomes another event, a proxy path disables TLS identity, a browser-origin WebSocket inherits a user session, or a body parser accepts attacker-chosen allocation size.

Triage

  1. Patch eventsource-encoder, Instana exporter, Volcano, monetr, and Phoenix where present; isolate or disable Cline Kanban Server exposure until an upstream fix is available.
  2. For WebSocket UIs and agent dashboards, require strict Origin checks, unpredictable connection tokens, and same-site/session-binding checks before accepting frames.
  3. Audit telemetry exporters configured with HTTP proxies; verify they still perform certificate-chain and hostname validation against the intended collector.
  4. Add body-size limits before JSON, NDJSON, webhook, and admission-review parsing.
  5. Hunt for unexpected SSE event names/IDs, Cline Kanban cross-origin traffic, Volcano webhook OOM/restart events, and monetr link-refresh fetches to loopback, metadata, RFC1918, or link-local addresses.

Durable controls

  • Encode SSE event, id, and data as separate fields with CR/LF rejection; never concatenate raw user strings into stream frames.
  • Treat proxy support as an alternate transport, not an alternate trust model: TLS verification must survive proxy mode.
  • Put explicit max bytes/read deadlines in front of every webhook and long-poll body parser.
  • Gate WebSockets on Origin, per-session nonce, authentication, and authorization before any state-changing message.
  • Centralize SSRF egress policy for link preview, refresh, webhook, and connector features.