pacquet before 12.0.0-alpha.5 Path Traversal via lockfile alias
pacquet, the Rust package-manager component shipped in the pnpm npm package versions >=12.0.0-alpha.0 and <12.0.0-alpha.5, does not validate dependency alias/name paths taken from a lockfile before using them in install-time filesystem joins. When a user installs a project with an attacker-supplied lockfile using --trust-lockfile or a frozen lockfile, alias entries containing path traversal segments (for example '../../escaped-link') are used when creating dependency and package links, bin destinations, hoisted entries, and virtual-store slots, allowing symlinks and directories to be created outside the intended project and node_modules boundary. Version 12.0.0-alpha.5 validates dependency names and every virtual-store slot path with a shared safe-join containment helper before any filesystem materialization, rejecting traversal, absolute, platform-specific, and reserved names with ERR_PNPM_INVALID_DEPENDENCY_NAME.
- Published
- Sep 27, 2026
- Updated
- Sep 27, 2026
- EPSS
- 0.3% · 16th percentile
- CWE
- CWE-22
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Report tools
Action score
28
Monitor
Low priority for now.
- CVSS
- 28 / 40 · 7.1 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.3%
CNA vs NVD score
- NVD
- —
- CNA · VulnCheck
- 7.1
- NVD has not scored this yet; the score shown is the CNA’s.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Affected systems
—
Versions reported by the vendor
Affected version ranges reported by the assigning authority (VulnCheck). Independent of NVD's CPE analysis and usually ahead of it.
pnpm pnpm
- 12.0.0-alpha.5not affected
- 12.0.0-alpha.0 and later · before 12.0.0-alpha.5affected · semver
Same product
pnpm: all recordsOther highest-scoring records for the same primary product.
- CVE-2025-69264pnpm v10+ Bypass "Dependency lifecycle scripts execution disabled by default"39Monitor
- CVE-2023-37478pnpm incorrectly parses tar archives relative to specification39Monitor
- CVE-2026-55698pnpm: Project env lockfile can short-circuit package-manager resolution and execute lockfile-selected pnpm bytes35Monitor
- CVE-2026-55697pnpm: Repository-controlled configDependencies can select a pacquet native install engine35Monitor
- CVE-2026-55487pnpm: manifest identity spoof satisfies allowBuilds and runs attacker lifecycle35Monitor
- CVE-2026-50016pnpm: Transitive dependency alias path traversal allows project path override via symlink replacement35Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| pnpm pnpm | 12.0.0-alpha.5 | Vendor (CNA) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
- CVE-2026-5919583 days apartpnpm: Path traversal in configDependencies env lockfile allows symlink creation outside node_modules/.pnpm-config32Monitor
- CVE-2026-8239327 days apartpnpm: A tarball dependency's manifest `name` escapes node_modules → arbitrary file write/overwrite on install30Monitor
- CVE-2026-5001594 days apartpnpm: Arbitrary File Write/Delete via Malicious Patch File (Path Traversal)29Monitor
- CVE-2026-8239227 days apartpnpm: Virtual store linker path traversal via unvalidated depPath name in lockfileToDepGraph28Monitor
- CVE-2026-5919483 days apartpnpm: patch-remove could delete project-selected files outside the patches directory28Monitor
- CVE-2026-5919683 days apartpnpm: hoisted install imports lockfile alias outside node_modules28Monitor
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- Integrity
- Availability
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- P
- Scope
- X
Weakness class (CWE)
CWE-22 · Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')CVSS vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
nvd-secondary
Root cause
A user-supplied file name is joined with the allowed directory, but the result is never checked to confirm it is still inside that directory.
The bug in code
The whole CWE-22 classA representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.
Vulnerable
const file = path.join(ROOT, req.query.name);res.sendFile(file);Fixed
const file = path.resolve(ROOT, req.query.name);if (!file.startsWith(ROOT + path.sep)) { return res.sendStatus(400);}res.sendFile(file);Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
- Path TraversalCAPEC-126likelihood: High · Very High
- Using Slashes and URL Encoding Combined to Bypass Validation LogicCAPEC-64likelihood: High · High
- Manipulating Web Input to File System CallsCAPEC-76likelihood: High · Very High
- Using Escaped Slashes in Alternate EncodingCAPEC-78likelihood: High · High
- Using Slashes in Alternate EncodingCAPEC-79likelihood: High · High
ATT&CK techniques
—
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for all 385,000+ vulnerabilities; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpChange log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
- github.com/pnpm/pnpm/security/advisories/GHSA-2rx9-3g3h-c2jv
- www.vulncheck.com/advisories/pacquet-before-12.0.0-alpha.5-path-traversal-via-lockfile-alias
Vendor advisories and official records. Exploit/PoC links are deliberately left out.