CVE-2026-55448 — mise
MEDIUMCVE-2026-55448 is a medium-severity (CVSS 6.3) OS Command Injection vulnerability in mise. A fix is available for mise — see the affected versions and patch details below.
mise: Local credential_command executes untrusted config
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.
- A successful exploit gives an attacker total control of the affected component, not partial access.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-55448.
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-2026-55448 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 377,166 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
miseReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects crates.io packages — download data is not available via public APIs for these ecosystems.
Description
mise manages dev tools like node, python, cmake, and terraform. From 2026.3.15 until 2026.6.4, mise loads github.credential_command from local project config before any trust decision, then executes that value with sh -c when resolving a GitHub token. An attacker who can place a .mise.toml in a repository can execute arbitrary shell commands when the victim runs a GitHub-related mise command and no higher-priority GitHub token environment variable is set. This vulnerability is fixed in 2026.6.4.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🦀crates.io | mise | ≥ 2026.3.15&&< 2026.6.4 | 2026.6.4cargo update -p mise --precise 2026.6.4 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for mise, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update mise to 2026.6.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-55448 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-2026-55448 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-55448. 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-2026-55448 in your dependencies?
O3 Security finds CVE-2026-55448 across crates.io dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.