CVE-2026-23890 is a medium-severity security vulnerability in pnpm (npm), affecting versions < 10.28.1. It is fixed in 10.28.1.
Summary A path traversal vulnerability in pnpm's bin linking allows malicious npm packages to create executable shims or symlinks outside of nodemodules/.bin. Bin names starting with @ bypass validation, and after scope normalization, path traversal sequences like ../../ remain intact. Details The vulnerability exists in the bin name validation and normalization logic: Validation Bypass (pkg-manager/package-bins/src/index.ts) The filter allows any bin name starting with @ to pass through without validation: Incomplete Normalization (pkg-manager/package-bins/src/index.ts) Exploitation (pkg-manager/link-bins/src/index.ts:288) The normalized name is used directly in path.join() without validation. PoC Create a malicious package: Install the package: Observe .npmrc created in project root (outside nodemodules/.bin). Impact All pnpm users who install npm packages CI/CD pipelines using pnpm Can overwrite config files, scripts, or other sensitive files Verified on pnpm main @ commit 5a0ed1d45.
CVE-2026-23890 has a CVSS score of 6.5 (Medium). The vector is network-reachable, no privileges required, and user interaction required. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment.
A fixed version is available (10.28.1). Upgrading removes the vulnerable code path.
npm
pnpm (< 10.28.1)pnpm → 10.28.1 (npm)Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter instead of chasing every advisory.
Kodem's runtime-powered SCA identifies whether CVE-2026-23890 is reachable in your applications. Explore open-source security for your team.
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Already deployed Kodem? See CVE-2026-23890 in your environment →Upgrade pnpm to 10.28.1 or later to resolve this vulnerability.
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CVE-2026-23890 is a medium-severity security vulnerability in pnpm (npm), affecting versions < 10.28.1. It is fixed in 10.28.1.
CVE-2026-23890 has a CVSS score of 6.5 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
pnpm (npm) versions < 10.28.1 is affected.
Yes. CVE-2026-23890 is fixed in 10.28.1. Upgrade to this version or later.
Whether CVE-2026-23890 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
Upgrade pnpm to 10.28.1 or later.