CVE-2026-44423 — shellhub
MEDIUMCVE-2026-44423 is a medium-severity (CVSS 6.5) CWE-639 vulnerability in github.com/shellhub-io/shellhub. A fix is available for github.com/shellhub-io/shellhub — see the affected versions and patch details below.
ShellHub: Cross-tenant IDOR in `GET /api/sessions/:uid` discloses SSH session data
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-44423.
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
CVE-2026-44423 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 377,333 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/shellhub-io/shellhubReal-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
ShellHub is a centralized SSH gateway. Prior to 0.24.2, GET /api/sessions/:uid returns the full session object for any authenticated caller, without scoping by the caller's tenant. An authenticated user can read session records (SSH username, device UID, remote IP, terminal type, authenticated flag, timestamps) belonging to any other namespace. This vulnerability is fixed in 0.24.2.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/shellhub-io/shellhub | all versions | 0.24.2go get github.com/shellhub-io/shellhub@v0.24.2 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/shellhub-io/shellhub, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/shellhub-io/shellhub to 0.24.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-44423 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 CVE-2026-44423 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-44423. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-44423 in your dependencies?
O3 Security finds CVE-2026-44423 across Go dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.