GHSA-55v3-xh23-96gh — v2
MEDIUMGHSA-55v3-xh23-96gh is a medium-severity (CVSS 6.5) Information Exposure vulnerability in github.com/cli/go-gh/v2. A fix is available for github.com/cli/go-gh/v2 — see the affected versions and patch details below.
`auth.TokenForHost` violates GitHub host security boundary when sourcing authentication token within a codespace
Exploitation Status
No confirmed exploitation observed yet
- A successful exploit gives an attacker total control of the affected component, not partial access.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for GHSA-55v3-xh23-96gh.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
GHSA-55v3-xh23-96gh plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 379,145 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
github.com/cli/go-gh/v2🐹github.com/cli/go-ghReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
Summary
A security vulnerability has been identified in go-gh that could leak authentication tokens intended for GitHub hosts to non-GitHub hosts when within a codespace.
Details
go-gh sources authentication tokens from different environment variables depending on the host involved:
GITHUB_TOKEN,GH_TOKENfor GitHub.com and ghe.comGITHUB_ENTERPRISE_TOKEN,GH_ENTERPRISE_TOKENfor GitHub Enterprise Server
Prior to 2.11.1, auth.TokenForHost could source a token from the GITHUB_TOKEN environment variable for a host other than GitHub.com or ghe.com when within a codespace.
In 2.11.1, auth.TokenForHost will only source a token from the GITHUB_TOKEN environment variable for GitHub.com or ghe.com hosts.
Impact
Successful exploitation could send authentication token to an unintended host.
Remediation and mitigation
- Upgrade
go-ghto2.11.1 - Advise extension users to regenerate authentication tokens:
- Advise extension users to review their personal security log and any relevant audit logs for actions associated with their account or enterprise
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/cli/go-gh/v2 | all versions | 2.11.1go get github.com/cli/go-gh/v2@v2.11.1 |
| 🐹Go | github.com/cli/go-gh | all versions | No fix |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/cli/go-gh/v2, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/cli/go-gh/v2 to 2.11.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-55v3-xh23-96gh is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-55v3-xh23-96gh can be triaged on real exposure rather than presence alone.
Tailored to GHSA-55v3-xh23-96gh. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
Frequently Asked Questions
Is GHSA-55v3-xh23-96gh in your dependencies?
O3 Security finds GHSA-55v3-xh23-96gh across Go dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.