CVE-2026-105858 is a high-severity (CVSS 8.1) Code Injection vulnerability in payload. A fix is available for payload — see the affected versions and patch details below.
Payload: Remote Code Execution through first-register
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 CVE-2026-105858.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2026-105858 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 394,803 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
payloadnpmDescription
Impact
A crafted request to the public first-register operation can be used to perform a RCE exploit.
You are affected if:
- You use local auth strategy and your application remains without an initial user created
Patches
In the patched version data submission to create first user is properly sanitized.
Users should upgrade Payload packages to >= 3.90.0 or >= 4.0.0-canary.34.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | payload | all versions | 3.90.0npm install payload@3.90.0 |
| 📦npm | payload | ≥ 4.0.0-canary.0&&< 4.0.0-canary.34 | 4.0.0-canary.34npm install payload@4.0.0-canary.34 |
Affected Products
payloadpayloadcmsDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for payload, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update payload to 3.90.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-105858 is resolved across your whole dependency graph.
Workarounds
Stop passing untrusted input into the interpreter or shell: call the affected binary with an argument array rather than a composed command string, reject anything outside a strict allowlist of expected values, and run the component under an account that cannot reach beyond the work it legitimately does.
Frequently Asked Questions
Is CVE-2026-105858 in your dependencies?
Find it across npm, including transitive dependencies.