Octo STS (github.com/octo-sts/app) before 0.11.2 returns trust policy configuration to callers whose OIDC token does not satisfy that policy. TrustPolicy.CheckToken included the policy's issuer, subject and audience values or patterns and claim_pattern names and regular expressions in its PermissionDenied errors, which Exchange returned verbatim. Exchange also selected the GitHub App installation before checking the token, so errors from resolving the policy's app or app_pattern pin were returned to callers the policy does not trust. An attacker who holds any validly signed OIDC token, such as a GitHub Actions token from a repository they own, and who knows or guesses a target owner/repo and identity name can read that policy's matching rules, even when the policy is stored in a private repository. These rules often name internal repositories, branches, environments or cloud account identifiers. The issue does not allow minting tokens or bypassing a trust policy. This issue is fixed in 0.11.2.
History

Tue, 03 Nov 2026 17:00:00 +0000

Type Values Removed Values Added
First Time appeared Octo-sts
Octo-sts app
Vendors & Products Octo-sts
Octo-sts app

Tue, 03 Nov 2026 01:00:00 +0000

Type Values Removed Values Added
Description Octo STS (github.com/octo-sts/app) before 0.11.2 returns trust policy configuration to callers whose OIDC token does not satisfy that policy. TrustPolicy.CheckToken included the policy's issuer, subject and audience values or patterns and claim_pattern names and regular expressions in its PermissionDenied errors, which Exchange returned verbatim. Exchange also selected the GitHub App installation before checking the token, so errors from resolving the policy's app or app_pattern pin were returned to callers the policy does not trust. An attacker who holds any validly signed OIDC token, such as a GitHub Actions token from a repository they own, and who knows or guesses a target owner/repo and identity name can read that policy's matching rules, even when the policy is stored in a private repository. These rules often name internal repositories, branches, environments or cloud account identifiers. The issue does not allow minting tokens or bypassing a trust policy. This issue is fixed in 0.11.2.
Title Octo STS discloses trust policy contents to unauthorized callers via Exchange error messages
Weaknesses CWE-209
References
Metrics cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: chainguard

Published: 2026-11-03T00:41:24.502Z

Updated: 2026-11-03T00:41:24.502Z

Reserved: 2026-10-05T19:21:04.930Z

Link: CVE-2026-105770

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Deferred

Published: 2026-11-03T01:16:44.147

Modified: 2026-11-03T16:30:49.290

Link: CVE-2026-105770

cve-icon Redhat

No data.