hughsk flat index.js unflatten prototype pollution
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and GitHub.
Summary
A vulnerability, which was classified as critical, was found in hughsk flat up to 5.0.0. This affects the function unflatten of the file index.js. The manipulation leads to improperly controlled modification of object prototype attributes ('prototype pollution'). It is possible to initiate the attack remotely. Upgrading to version 5.0.1 is able to address this issue. The name of the patch is 20ef0ef55dfa028caddaedbcb33efbdb04d18e13. It is recommended to upgrade the affected component. The identifier VDB-216777 was assigned to this vulnerability.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| hughsk | flat | 5.0 | — | No fix listed | CNA |
| — | flat (npm) | before 1.6.2 | 1.6.2 | Patch available | GHSA-2j2x-2gpw-g8fm |
| — | flat (npm) | 2.0.0 to before 2.0.2 | 2.0.2 | Patch available | GHSA-2j2x-2gpw-g8fm |
| — | flat (npm) | 3.0.0 to before 3.0.1 | 3.0.1 | Patch available | GHSA-2j2x-2gpw-g8fm |
| — | flat (npm) | 4.0.0 to before 4.0.2 | 4.0.2 | Patch available | GHSA-2j2x-2gpw-g8fm |
| — | flat (npm) | 5.0.0 to before 5.0.1 | 5.0.1 | Patch available | GHSA-2j2x-2gpw-g8fm |
- flat Vendorhughsk Affected 5.0 Fixed in — No fix listed CNA
- flat (npm) Vendor— Affected before 1.6.2 Fixed in 1.6.2 Patch available GHSA-2j2x-2gpw-g8fm
- flat (npm) Vendor— Affected 2.0.0 to before 2.0.2 Fixed in 2.0.2 Patch available GHSA-2j2x-2gpw-g8fm
- flat (npm) Vendor— Affected 3.0.0 to before 3.0.1 Fixed in 3.0.1 Patch available GHSA-2j2x-2gpw-g8fm
- flat (npm) Vendor— Affected 4.0.0 to before 4.0.2 Fixed in 4.0.2 Patch available GHSA-2j2x-2gpw-g8fm
- flat (npm) Vendor— Affected 5.0.0 to before 5.0.1 Fixed in 5.0.1 Patch available GHSA-2j2x-2gpw-g8fm
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:flat_project:flat:*:*:*:*:*:*:*:* | before 5.0.1 | Vulnerable | Flat Project |
- cpe:2.3:a:flat_project:flat:*:*:*:*:*:*:*:* Versions before 5.0.1 Vulnerable ·Flat Project
Remediation
- Fix · GHSA-2j2x-2gpw-g8fm flat (npm) Fixed in 1.6.2 Advisory →
- Fix · GHSA-2j2x-2gpw-g8fm flat (npm) Fixed in 2.0.2 Advisory →
- Fix · GHSA-2j2x-2gpw-g8fm flat (npm) Fixed in 3.0.1 Advisory →
- Fix · GHSA-2j2x-2gpw-g8fm flat (npm) Fixed in 4.0.2 Advisory →
- Fix · GHSA-2j2x-2gpw-g8fm flat (npm) Fixed in 5.0.1 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2020-36632
- 2026-10-03 Alias added: GHSA-2j2x-2gpw-g8fm
References
Patch 3
More hughsk vulnerabilities
- TI-2026-82409 Denial of service in flat via unflatten() numeric array index keys CVSS 4.0HIGH 8.2
Sources
- CVE-2020-36632 · CVE Program
- CVE-2020-36632 · NVD
- FIRST EPSS
- GHSA-2j2x-2gpw-g8fm · GitHub Advisory Database · CC BY 4.0
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