Octo-STS Vulnerable to Unauthenticated SSRF with HTTP Response Reflection in OIDC Flow

Open Source Vulnerabilities CVE-2025-52477

Octo-STS is a GitHub App that acts like a Security Token Service (STS) for the GitHub API. Octo-STS versions before v0.5.3 are vulnerable to unauthenticated SSRF by abusing fields in OpenID Connect tokens. Malicious tokens were shown to trigger internal network requests which could reflect error logs with sensitive information. Upgrade to v0.5.3 to resolve this issue. This version includes patch sets to sanitize input and redact logging.

Open Source Vulnerabilities GHSA-h3qp-hwvr-9xcq

## Summary Octo-STS versions before v0.5.3 are vulnerable to unauthenticated SSRF by abusing fields in OpenID Connect tokens. Malicious tokens were shown to trigger internal network requests which could reflect error logs with sensitive information. Please upgrade to v0.5.3 to resolve this issue. This version includes patch sets to [sanitize input](https://github.com/octo-sts/app/commit/b3976e39bd8c8c217c0670747d34a4499043da92) and [redact logging](https://github.com/octo-sts/app/commit/0f177fde54f9318e33f0bba6abaea9463a7c3afd). Many thanks to @vicevirus for reporting this issue and for assisting with remediation review. ## References - https://github.com/octo-sts/app/security/advisories/GHSA-h3qp-hwvr-9xcq - https://github.com/octo-sts/app/commit/b3976e39bd8c8c217c0670747d34a4499043da92 - https://github.com/octo-sts/app/commit/0f177fde54f9318e33f0bba6abaea9463a7c3afd

Open Source Vulnerabilities GO-2025-3779

Octo STS Unauthenticated SSRF by abusing fields in OpenID Connect tokens in github.com/octo-sts/app