CVSS 4.0
8.8 highCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:NCVE-2025-55164
High (8.8). EPSS 0.4% chance of exploitation in the next 30 days. Fixed in content-security-policy-parser 0.6.0.
content-security-policy-parser parses content security policy directives. A prototype pollution vulnerability exists in versions 0.5.0 and earlier, wherein if a policy name is called __proto__, one can override the Object prototype. This issue has been patched in version 0.6.0. A workaround involves disabling prototype method in NodeJS, neutralizing all possible prototype pollution attacks. Provide either --disable-proto=delete (recommended) or --disable-proto=throw as an argument to node to enable this feature.
Severity
- EPSS
- 0.4% chance of exploitation in the next 30 days; higher than 38% of CVEs (scores of 2026-10-31)
- CWE
- CWE-1321
- Published
- Modified
- Record from
- the NVD, synced
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-w2cq-g8g3-gm83 | npm | content-security-policy-parser | <0.6.0 | 0.6.0 |
References
- https://github.com/helmetjs/content-security-policy-parser/commit/b13a52554f0168af393e3e38ed4a94e9e6aea9dc
- https://github.com/helmetjs/content-security-policy-parser/issues/11
- https://github.com/helmetjs/content-security-policy-parser/security/advisories/GHSA-w2cq-g8g3-gm83
- https://www.vicarius.io/vsociety/posts/cve-2025-55164-detect-node-csp-parser-vulnerability
- https://www.vicarius.io/vsociety/posts/cve-2025-55164-mitigate-csp-parser-vulnerability