SSRF in Octo-Sts App

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.

Vulnerability class: SSRF (Server-Side Request Forgery)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 8.6 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N.

EPSS exploit prediction

EPSS: 0.005 (39.6th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 40th percentile — 39.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2025-52477: held from 0.004 to 0.005.

EPSS over last 30 days · oldest: 0.004 · newest: 0.005 · change: +0.001

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2025-52477?
CVE-2025-52477 is a high-severity vulnerability in Octo-Sts App, classified under Server-Side Request Forgery (SSRF). CVSS score: 8.6/10. Published 2025-06-26.
How severe is CVE-2025-52477?
High severity. CVSS v3 base score is 8.6 out of 10.