Configuration Override in helmet-csp
Key facts
- Attack vector
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- Privileges required
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- User interaction
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- Attack complexity
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- Impact type
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- Confidentiality · integrity · availability
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- Fix status
- Fixed
No CVSS vector from any source. Fix status from GitHub.
Summary
Versions of `helmet-csp` before to 2.9.1 are vulnerable to a Configuration Override affecting the application's Content Security Policy (CSP). The package's browser sniffing for Firefox deletes the `default-src` CSP policy, which is the fallback policy. This allows an attacker to remove an application's default CSP, possibly rendering the application vulnerable to Cross-Site Scripting. ## Recommendation Upgrade to version 2.9.1 or later. Setting the `browserSniff` configuration to `false` in vulnerable versions also mitigates the issue.
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 |
|---|---|---|---|---|---|
| — | helmet-csp (npm) | 1.2.2 to before 2.9.1 | 2.9.1 | Patch available | GHSA-c3m8-x3cg-qm2c |
- helmet-csp (npm) Vendor— Affected 1.2.2 to before 2.9.1 Fixed in 2.9.1 Patch available GHSA-c3m8-x3cg-qm2c
Remediation
- Fix · GHSA-c3m8-x3cg-qm2c helmet-csp (npm) Fixed in 2.9.1 Advisory →
Timeline
- 2026-10-03 Threatist record created from GHSA-c3m8-x3cg-qm2c
References
Sources
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences