PYSEC-2026-3572 
## Summary
Numerous HTTP-emitting modules (`core.api.http_get`, `core.api.http_post`, `graphql.query`/`graphql.mutation`, `monitor.http_check`, `communication.slack_send`, `notification.{discord,slack,teams}.send_message`, `ai.vision_analyze` [anthropic path], `verify.visual_diff`, `browser.proxy_rotate`, and the `agent`/`llm` inline base_url branch) perform outbound requests to a fully client-controlled URL **without calling the project's own SSRF guard** (`validate_url_with_env_config`) that their sibling modules apply. An authenticated workflow-author can point the URL at the cloud metadata IP (169.254.169.254), a loopback/RFC1918 host, or any internal host and read the response, yielding cloud-metadata credential theft and internal service read/write.

## Root Cause
The SSRF guard is per-module (there is NO global egress interception). Each module must call `validate_url_with_env_config` before issuing a request. The listed modules never call it — they only carry an `ssrf_protected` **metadata tag string** which enforces nothing. Exemplar: `src/core/modules/third_party/developer/http/requests.py` — grepping for `validate_url|ssrf|is_private` in requests.py returns 0 guard calls; `session.get(url)` fires at `:85` (HTTPGetModule) and `session.post` at `:188` (HTTPPostModule). SECURITY.md incorrectly lists `api.http_get` as SSRF-protected.

## Impact
Readable SSRF: full `{status_code, headers, body}` returned to the caller (requests.py:96-108). Enables theft of cloud IAM credentials from the metadata endpoint and read/write access to internal-only APIs. Scope Changed (S:C) — the request crosses into cloud-metadata / internal-network authority the workflow layer does not otherwise have.

## Proof of Concept
Verified live this session: `core.api.http_get` with `url` pointed at a loopback internal server returned the internal body `INTERNAL-SECRET-IAM-CREDENTIALS`, while the guarded sibling `http.get` returned `NETWORK_ERROR: Hostname blocked: 127.0.0.1` on the same input — proving the branch-asymmetry is real (not a port artifact).
```
POST /mcp {"method":"tools/call","params":{"name":"execute_module",
  "arguments":{"module_id":"core.api.http_get",
  "params":{"url":"http://<cloud-metadata-ip>/latest/meta-data/iam/security-credentials/"}}}}
```

## Attack Chain
1. Entry: authenticated MCP client → `POST /mcp` execute_module `core.api.http_get`, url set to the cloud metadata endpoint. Guard: `require_auth` (mcp.py:71). Bypass proof: passes with a valid workflow-author bearer token (PR:L).
2. Check: capability denylist / `enforce_module_policy` (base.py:240). Bypass proof: `core.api.*` not in `_DEFAULT_DENYLIST` (module_policy.py:45-67) → `is_allowed=True` (runtime-registration verified: `core.api.http_get -> HTTPGetModule`).
3. Check: SSRF validation. Bypass proof: `requests.py` has ZERO `validate_url`/ssrf calls — only the `ssrf_protected` tag string at :23/:116. `session.get(url)` fires at :85.
4. Sink: aiohttp GET/POST to the cloud metadata IP.
5. Impact: full response body returned → IAM credential theft, internal read/write.

## Bypass Evidence
Grepping `validate_url|ssrf|is_private` in requests.py → 0 guard calls (2 hits are both the inert tag string). Live PoC returned internal body directly; guarded sibling blocked the same input. Direct IP works — no IPv6 transition trick needed (AC:L), unlike the seed CVE-2026-55787.

## Affected Versions
`<= 2.26.6` — code present on latest release tag v2.26.6 (`requests.py:19,112`).

## Suggested Fix
Call `validate_url_with_env_config(url)` in each listed module before issuing the outbound request, matching the guarded siblings (e.g. `ai.model:157`, `http.get`). Best: route all outbound HTTP through a single guarded client wrapper so new modules inherit the guard.

## Credit

Vulnerability discovered by zx (Jace).
CVSS v3.1 score: 8.5