Summary
Flyto2 Core: Multiple HTTP-family modules fetch client-controlled URLs without the SSRF guard their siblings apply (SSRF to internal/metadata)
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.
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
- Entry: authenticated MCP client →
POST /mcpexecute_modulecore.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). - 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). - Check: SSRF validation. Bypass proof:
requests.pyhas ZEROvalidate_url/ssrf calls, only thessrf_protectedtag string at :23/:116.session.get(url)fires at :85. - Sink: aiohttp GET/POST to the cloud metadata IP.
- 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).
Credit
Vulnerability discovered by zx (Jace).
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.
Untrusted input controls the target URL of a server-initiated request, which may reach internal services not otherwise accessible from outside. Typical impact: access to internal metadata services, internal APIs, or cloud credentials.
CVE-2026-67428 has a CVSS score of 8.5 (High). The vector is network-reachable, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (2.26.7); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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See it in your environmentNew to Kodem? Get a demo →Remediation advice
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.
Frequently Asked Questions
- What is CVE-2026-67428? CVE-2026-67428 is a high-severity server-side request forgery (SSRF) vulnerability in flyto-core (pip), affecting versions <= 2.26.6. It is fixed in 2.26.7. Untrusted input controls the target URL of a server-initiated request, which may reach internal services not otherwise accessible from outside.
- How severe is CVE-2026-67428? CVE-2026-67428 has a CVSS score of 8.5 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of flyto-core are affected by CVE-2026-67428? flyto-core (pip) versions <= 2.26.6 is affected.
- Is there a fix for CVE-2026-67428? Yes. CVE-2026-67428 is fixed in 2.26.7. Upgrade to this version or later.
- Is CVE-2026-67428 exploitable, and should I be worried? Whether CVE-2026-67428 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-67428 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-67428? Upgrade
flyto-coreto 2.26.7 or later.