fix(slack): prevent undici dispatcher leak to globalThis.fetch causing media download failure Markdown by openperf · Pull Request #62239 · openclaw/openclaw

openperf · 2026-04-07T02:09:58Z

Summary

Problem: Slack file and image attachments fail to download silently. The issue occurs in extensions/slack/src/monitor/media.ts where createSlackMediaFetch is used.
Root Cause: The SSRF guard (fetchWithSsrFGuard) creates an undici 8.x dispatcher and passes it in the init object to the custom fetchImpl. Inside createSlackMediaFetch, the init object is destructured using ...rest and passed directly to globalThis.fetch (Node's built-in fetch, which uses undici 7.x). The built-in fetch does not recognize the undici 8.x dispatcher's onRequestStart method, throwing an InvalidArgumentError which is then silently swallowed by a catch { return null; } block in resolveSlackMedia.
Fix: Explicitly destructure and exclude the dispatcher property from the init object inside createSlackMediaFetch before passing ...rest to globalThis.fetch. This prevents the incompatible project-level undici dispatcher from leaking into the Node-bundled fetch runtime.
What changed:
- extensions/slack/src/monitor/media.ts: Stripped dispatcher from init in createSlackMediaFetch.
- extensions/slack/src/monitor/media.test.ts: Added a unit test to verify dispatcher is not forwarded to globalThis.fetch.
What did NOT change (scope boundary): The SSRF guard logic itself, other extensions' fetch implementations, and the general Slack media resolution flow remain unchanged.

Reproduction

Configure a Slack bot with the OpenClaw gateway.
Send a message containing an image or file attachment in a monitored Slack channel.
Observe that the bot fails to download the attachment (no placeholder or file is saved), and no error is logged.

Risk / Mitigation

Risk: The SSRF guard relies on the dispatcher to enforce network policies. Stripping it might bypass the SSRF protection for Slack media downloads.
Mitigation: This is safe because createSlackMediaFetch is only used for fetching from Slack's own CDN (files.slack.com etc.), which are trusted external URLs. The SSRF guard's primary purpose is to prevent access to internal/private networks, which is not a risk when fetching from known Slack domains. The added unit test ensures the dispatcher is correctly stripped without affecting the rest of the request initialization.

Change Type (select all)

Bug fix

Scope (select all touched areas)

Gateway
Slack Extension

Linked Issue/PR

Fixes #62218

greptile-apps · 2026-04-07T02:12:37Z

Greptile Summary

Strips the undici dispatcher from the init object inside createSlackMediaFetch before forwarding to globalThis.fetch, fixing silent Slack media download failures. The SSRF guard's undici 8.x dispatcher was leaking into Node's built-in fetch (which uses a different undici runtime), causing an InvalidArgumentError that was silently swallowed. SSRF policy enforcement remains intact at the fetchWithSsrFGuard layer — the hostname allowlist and pinned DNS resolution both run before the request reaches the custom fetch function. A regression test is included that verifies the dispatcher is not forwarded.

Confidence Score: 5/5

Safe to merge — the fix is minimal, well-scoped, and SSRF policy is still enforced at the fetch-guard layer before the dispatcher is used.

No P0 or P1 findings. The fix correctly strips the incompatible dispatcher at exactly the right boundary, SSRF protection is preserved via the allowlist and pinned-DNS checks in fetchWithSsrFGuard, and the regression test meaningfully validates the fix.

No files require special attention.

_{Reviews (1): Last reviewed commit: "fix(slack ): prevent undici dispatcher l..." | Re-trigger Greptile}

mjamiv · 2026-04-07T04:47:52Z

+1 from production — we confirmed this exact failure across 4 OpenShell sandbox agents on Node 22.22.1 with undici 8.0.2. All Slack file downloads silently broken since 2026.4.5.

Detailed root cause analysis and workaround posted on the companion PR #62241. Both PRs address the same underlying issue — the npm undici dispatcher leaking into Node's built-in fetch.

obviyus

Reviewed latest changes; landing now.

…ng media download failure

…openperf

…openperf)

obviyus · 2026-04-07T05:46:11Z

Landed on main.

Landed source commit: 6e48619
Merge commit: e8fb140

Thanks @openperf.

…hment downloads on Node 24+ The SSRF guard pinned-DNS dispatcher is an undici 8.x Agent, but Node 24 built-in globalThis.fetch uses undici 7.x internally. Passing the 8.x dispatcher to the native fetch causes 'invalid onRequestStart method' errors, breaking all BlueBubbles attachment downloads. Route through fetchWithRuntimeDispatcher (bundled undici own fetch) when a dispatcher is present, matching the approach used by the Slack extension (openclaw#62239). This preserves SSRF DNS pinning instead of stripping the dispatcher entirely.

…hment downloads on Node 24+ The SSRF guard pinned-DNS dispatcher is an undici 8.x Agent, but Node 24 built-in globalThis.fetch uses undici 7.x internally. Passing the 8.x dispatcher to native fetch causes 'invalid onRequestStart method' errors, breaking all BlueBubbles attachment downloads. Route through fetchWithRuntimeDispatcher (bundled undici own fetch) when a dispatcher is present, matching the Slack extension (openclaw#62239). Preserves SSRF DNS pinning, forwards opts.timeoutMs via AbortSignal.timeout (default 10s), and honours test-installed globalThis.fetch mocks via isMockedFetch guard.

…openperf

…openperf) * fix(slack ): prevent undici dispatcher leak to globalThis.fetch causing media download failure * fix(slack): preserve guarded media transport * fix: preserve Slack guarded media transport (openclaw#62239) (thanks @openperf) --------- Co-authored-by: Ayaan Zaidi <hi@obviy.us>

…openperf

…openperf) * fix(slack ): prevent undici dispatcher leak to globalThis.fetch causing media download failure * fix(slack): preserve guarded media transport * fix: preserve Slack guarded media transport (openclaw#62239) (thanks @openperf) --------- Co-authored-by: Ayaan Zaidi <hi@obviy.us>

…openperf

…openperf) * fix(slack ): prevent undici dispatcher leak to globalThis.fetch causing media download failure * fix(slack): preserve guarded media transport * fix: preserve Slack guarded media transport (openclaw#62239) (thanks @openperf) --------- Co-authored-by: Ayaan Zaidi <hi@obviy.us>

openclaw-barnacle Bot added channel: slack Channel integration: slack size: XS labels Apr 7, 2026

openperf mentioned this pull request Apr 7, 2026

[Bug]: Slack inbound file attachments silently fail in 2026.4.5 (undici 8.x SSRF dispatcher incompatible with Node built-in fetch) #62218

Closed

This was referenced Apr 7, 2026

globalThis.fetch (undici) does not honor HTTP_PROXY/HTTPS_PROXY env vars #62181

Closed

fix(audio): disable DNS pinning for multipart audio transcription requests #62174

Closed

obviyus force-pushed the fix/slack-media-ssrf-dispatcher branch from 8c40e16 to bf910ef Compare April 7, 2026 05:38

openclaw-barnacle Bot added the maintainer Maintainer-authored PR label Apr 7, 2026

obviyus self-assigned this Apr 7, 2026

obviyus approved these changes Apr 7, 2026

View reviewed changes

openperf and others added 3 commits April 7, 2026 11:13

fix(slack ): prevent undici dispatcher leak to globalThis.fetch causi…

8954d16

…ng media download failure

fix(slack): preserve guarded media transport

d833a87

fix: preserve Slack guarded media transport (openclaw#62239) (thanks @…

6e48619

…openperf)

obviyus force-pushed the fix/slack-media-ssrf-dispatcher branch from eb3ef65 to 6e48619 Compare April 7, 2026 05:45

obviyus merged commit e8fb140 into openclaw:main Apr 7, 2026
7 checks passed

obviyus mentioned this pull request Apr 7, 2026

fix(net): strip external undici dispatcher from custom fetchImpl calls #62241

Closed

3 tasks

martingarramon mentioned this pull request Apr 7, 2026

[Bug]: Agent is not being able to read files that were sent on Slack #62551

Closed

mjamiv mentioned this pull request Apr 8, 2026

Feature: Add global HTTP proxy support via environment variables #43821

Closed

github-actions Bot mentioned this pull request Apr 8, 2026

Update ghcr.io/openclaw/openclaw Docker tag to v2026.4.8 claytono/infra#1923

Merged

1 task

This was referenced Apr 8, 2026

[Bug]: 2026.4.5 regression: Slack private file images no longer visible (SSRF redirect fix breaks url_private_download fetch) #62960

Closed

fix(slack): preserve auth on same-origin media redirects #62996

Merged

martingarramon mentioned this pull request Apr 9, 2026

bug(slack): inbound attachments in container sandbox fail with placeholder-only turn and fetch error 'invalid onRequestStart method' #63905

Open

meimakes mentioned this pull request Apr 11, 2026

fix(bluebubbles): strip SSRF dispatcher from fetchImpl to fix attachment downloads #63984

Closed

coletebou mentioned this pull request Apr 13, 2026

fix(bluebubbles): route fetchImpl through bundled undici fetch on Node 24+ #66103

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2 tasks

coletebou mentioned this pull request Apr 13, 2026

fix(bluebubbles): route fetchImpl through bundled undici fetch on Node 24+ #66108

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4 tasks

clawsweeper Bot mentioned this pull request Apr 27, 2026

fix(slack): strip SSRF dispatcher from media fetch to prevent undici version conflict #64022

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fix(slack): prevent undici dispatcher leak to globalThis.fetch causing media download failure Markdown#62239

fix(slack): prevent undici dispatcher leak to globalThis.fetch causing media download failure Markdown#62239
obviyus merged 3 commits intoopenclaw:mainfrom
openperf:fix/slack-media-ssrf-dispatcher

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openperf commented Apr 7, 2026

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greptile-apps Bot commented Apr 7, 2026

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Confidence Score: 5/5

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