CVE-2025-52477: Octo-Sts App

High severity, CVSS 8.6. EPSS: 0.5% chance of exploitation in the next 30 days.

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.

Affected products

• Octo-Sts App: before 0.5.3 (fixed in 0.5.3)

Published 2025-06-26. Last modified 2026-06-17.