What’s Vulnerable › Vulnerabilities

CVE-2021-23518: Prototype Pollution

• Severity: critical (CVSS 9.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.9% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2022-01-21 · updated 2026-06-17
• Weakness: CWE-1321

Description

The package cached-path-relative before 1.1.0 are vulnerable to Prototype Pollution via the cache variable that is set as {} instead of Object.create(null) in the cachedPathRelative function, which allows access to the parent prototype properties when the object is used to create the cached relative path. When using the origin path as __proto__, the attribute of the object is accessed instead of a path. **Note:** This vulnerability derives from an incomplete fix in https://security.snyk.io/vuln/SNYK-JS-CACHEDPATHRELATIVE-72573

Affected products

• Cached-Path-Relative Project Cached-Path-Relative: before 1.1.0 — fixed in 1.1.0
• Debian Linux: 10.0

How to fix

Upgrade to a fixed version: Cached-Path-Relative Project Cached-Path-Relative 1.1.0. Check the vendor advisory for mitigations.

References

• https://github.com/ashaffer/cached-path-relative/commit/40c73bf70c58add5aec7d11e4f36b93d144bb760
• https://lists.debian.org/debian-lts-announce/2022/12/msg00006.html
• https://snyk.io/vuln/SNYK-JAVA-ORGWEBJARSNPM-2348246
• https://snyk.io/vuln/SNYK-JS-CACHEDPATHRELATIVE-2342653
• https://github.com/ashaffer/cached-path-relative/commit/40c73bf70c58add5aec7d11e4f36b93d144bb760
• https://lists.debian.org/debian-lts-announce/2022/12/msg00006.html
• https://snyk.io/vuln/SNYK-JAVA-ORGWEBJARSNPM-2348246
• https://snyk.io/vuln/SNYK-JS-CACHEDPATHRELATIVE-2342653

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