How severe is CVE-2026-23889?

CVE-2026-23889 has a CVSS score of 6.5/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2026-23889?

CVE-2026-23889 affects the following packages: pnpm (npm). Ecosystems affected: npm.

How do I fix CVE-2026-23889?

Update pnpm to 10.28.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-23889 is resolved across your whole dependency graph.

How do I detect CVE-2026-23889 in my npm dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for pnpm. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate CVE-2026-23889 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against CVE-2026-23889?

O3 pinpoints whether CVE-2026-23889 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is CVE-2026-23889 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-23889 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2026-23889?

CVE-2026-23889 has an EPSS (Exploit Prediction Scoring System) score of 0.4%, placing it in the 34th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

When was CVE-2026-23889 published, and has it been updated?

CVE-2026-23889 was published on January 26, 2026 and was last updated on April 10, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

📦 npm

CVE-2026-23889

MEDIUM

pnpm has Windows-specific tarball Path Traversal

Also known asGHSA-6x96-7vc8-cm3p

Published

Jan 26, 2026

Updated

Apr 10, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

EPSS Exploitation Probability

via FIRST.org ↗

0.4%probability of exploitation in next 30 days

Lower Risk34th percentile+0.41%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Blast Radius

1 pkg affected

📦pnpm

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects npm packages — download data is not available via public APIs for these ecosystems.

Description

pnpm is a package manager. Prior to version 10.28.1, a path traversal vulnerability in pnpm's tarball extraction allows malicious packages to write files outside the package directory on Windows. The path normalization only checks for ./ but not .\. On Windows, backslashes are directory separators, enabling path traversal. This vulnerability is Windows-only. This issue impacts Windows pnpm users and Windows CI/CD pipelines (GitHub Actions Windows runners, Azure DevOps). It can lead to overwriting .npmrc, build configs, or other files. Version 10.28.1 contains a patch.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`pnpm`	all versions	10.28.1

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for pnpm. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update pnpm to 10.28.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-23889 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-23889 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to CVE-2026-23889. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

pnpm is a package manager. Prior to version 10.28.1, a path traversal vulnerability in pnpm's tarball extraction allows malicious packages to write files outside the package directory on Windows. The path normalization only checks for `./` but not `.\`. On Windows, backslashes are directory separators, enabling path traversal. This vulnerability is Windows-only. This issue impacts Windows pnpm users and Windows CI/CD pipelines (GitHub Actions Windows runners, Azure DevOps). It can lead to overwriting `.npmrc`, build configs, or other files. Version 10.28.1 contains a patch.

O3 Security · Impact-Aware SCA

Is CVE-2026-23889 in your dependencies?

O3 detects CVE-2026-23889 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

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