Prototype pollution in expand-object
Priority HIGH 70CWE-1321Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- —
- Confidentiality · integrity · availability
- Low · Low · Low
- Fix status
- No fix listed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA and GitHub.
Summary
Versions of the package expand-object from 0.0.0 are vulnerable to Prototype Pollution in the expand() function in index.js. This function expands the given string into an object and allows a nested property to be set without checking the provided keys for sensitive properties like __proto__.
Why it matters now
Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00423 36th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | expand-object | 0.0.0 and later | — | No fix listed | CNA |
| — | expand-object (npm) | up to 0.4.2 | — | No fix listed | GHSA-4vjr-hfpp-2m7w |
- expand-object Vendor— Affected 0.0.0 and later Fixed in — No fix listed CNA
- expand-object (npm) Vendor— Affected up to 0.4.2 Fixed in — No fix listed GHSA-4vjr-hfpp-2m7w
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2025-3197
- 2026-10-03 Alias added: GHSA-4vjr-hfpp-2m7w
References
Sources
- CVE-2025-3197 · CVE Program
- CVE-2025-3197 · NVD
- FIRST EPSS
- GHSA-4vjr-hfpp-2m7w · GitHub Advisory Database · CC BY 4.0
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