GHSA-8cc4-rfj6-fhg4
MEDIUMpnpm uses the md5 path shortening function causes packet paths to coincide, which causes indirect packet overwriting
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.
Blast Radius
Weekly download volume for affected packages — a proxy for how broadly this vulnerability is deployed.
pnpmnpmDescription
The path shortening function is used in pnpm：
export function depPathToFilename (depPath: string, maxLengthWithoutHash: number): string {
let filename = depPathToFilenameUnescaped(depPath).replace(/[\\/:*?"<>|]/g, '+')
if (filename.includes('(')) {
filename = filename
.replace(/\)$/, '')
.replace(/(\)\()|\(|\)/g, '_')
}
if (filename.length > maxLengthWithoutHash || filename !== filename.toLowerCase() && !filename.startsWith('file+')) {
return `${filename.substring(0, maxLengthWithoutHash - 27)}_${createBase32Hash(filename)}`
}
return filename
}
However, it uses the md5 function as a path shortening compression function, and if a collision occurs, it will result in the same storage path for two different libraries. Although the real names are under the package name /node_modoules/, there are no version numbers for the libraries they refer to.
In the diagram, we assume that two packages are called packageA and packageB, and that the first 90 digits of their package names must be the same, and that the hash value of the package names with versions must be the same. Then C is the package that they both reference, but with a different version number. (npm allows package names up to 214 bytes, so constructing such a collision package name is obvious.)
Then hash([email protected])=hash([email protected]). This results in the same path for the installation, and thus under the same directory. Although the package names under node_modoules are the full paths again, they are shared with C. What is the exact version number of C? In our local tests, it depends on which one is installed later. If packageB is installed later, the C version number will change to 2.0.0. At this time, although package A requires the [email protected] version, package. json will only work during installation, and will not affect the actual operation. We did not receive any installation error issues from pnpm during our local testing, nor did we use force, which is clearly a case that can be triggered.
For a package with a package name + version number longer than 120, another package can be constructed to introduce an indirect reference to a lower version, such as one with some known vulnerability. Alternatively, it is possible to construct two packages with more than 120 package names + version numbers. This is clearly an advantage for those intent on carrying out supply chain attacks.
The solution: The repair cost is also very low, just need to upgrade the md5 function to sha256.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | pnpm | all versions | 10.0.0 |
Detection & mitigation playbook
Open-source dependencyDetect
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 10.0.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-8cc4-rfj6-fhg4 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 GHSA-8cc4-rfj6-fhg4 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 GHSA-8cc4-rfj6-fhg4. 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-8cc4-rfj6-fhg4 in your dependencies?
O3 detects GHSA-8cc4-rfj6-fhg4 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.