VulnerabilityPublished 13 Aug 2026Updated 3 Nov 2026

CVE-2026-24131: Pnpm@9 · pnpm has Path Traversal via arbitrary file permission modification

Affects pnpm@9Source GCVE Database

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Not known to be exploited · CVSS 6.7 Medium.

Data as of 4 Nov 2026, 01:45 UTC

CVSS 4.0 base score

6.7Medium

How severe the flaw is on the 0–10 CVSS scale.

CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

Attack Vector: Local
Attack Complexity: Low
Attack Requirements: None
Privileges Required: None
User Interaction: Active
Vulnerable system confidentiality: High
Vulnerable system integrity: None
Vulnerable system availability: None
Subsequent system confidentiality: None
Subsequent system integrity: None
Subsequent system availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Local: The vulnerable system is not bound to the network stack and the attacker’s path is via read/write/execute capabilities. Either the attacker exploits the vulnerability by accessing the target system locally (e.g., keyboard, console), or through terminal emulation (e.g., SSH); or the attacker relies on User Interaction by another person to perform actions required to exploit the vulnerability (e.g., using social engineering techniques to trick a legitimate user into opening a malicious document).
Attack Complexity: Low: The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
Attack Requirements: None: The successful attack does not depend on the deployment and execution conditions of the vulnerable system. The attacker can expect to be able to reach the vulnerability and execute the exploit under all or most instances of the vulnerability.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack.
User Interaction: Active: Successful exploitation of this vulnerability requires a targeted user to perform specific, conscious interactions with the vulnerable system and the attacker’s payload, or the user’s interactions would actively subvert protection mechanisms which would lead to exploitation of the vulnerability.
Vulnerable system confidentiality: High: There is a total loss of confidentiality, resulting in all information within the Vulnerable System being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact. For example, an attacker steals the administrator's password, or private encryption keys of a web server.
Vulnerable system integrity: None: There is no loss of integrity within the Vulnerable System.
Vulnerable system availability: None: There is no impact to availability within the Vulnerable System.
Subsequent system confidentiality: None: There is no loss of confidentiality within the Subsequent System or all confidentiality impact is constrained to the Vulnerable System.
Subsequent system integrity: None: There is no loss of integrity within the Subsequent System or all integrity impact is constrained to the Vulnerable System.
Subsequent system availability: None: There is no impact to availability within the Subsequent System or all availability impact is constrained to the Vulnerable System.

Definitions: FIRST CVSS v4.0 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 13 Aug 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 3 Nov 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
Homebrewpnpm@9`pkg:brew/pnpm%409`Other threats	Affected >=9.15.4	Fixed in–

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AI-suggested

A fix is available by adding validation to ensure the 'directories.bin' path is a subdirectory of the package root before processing. The vendor's suggested fix is to apply an isSubdir() check on the resolved bin directory path and reject paths outside the package directory. Users should update pnpm to a version that includes this fix once released. Until then, avoid installing untrusted packages that specify a 'directories.bin' field with relative paths that could escape the package directory. No other mitigations are specifically recommended.

Description

pnpm version 9 contains a path traversal vulnerability in handling the 'directories.bin' field of package manifests. This flaw allows a malicious npm package to specify a relative path that escapes the package root directory, causing pnpm to change file permissions (chmod 755) on arbitrary files outside the package directory on Unix-like systems. Windows is not affected. The vulnerability arises because the path is joined without validation to ensure it remains within the package directory.

Impact

This vulnerability enables a supply-chain attack where a malicious npm package can cause pnpm to change file permissions on arbitrary files outside the package directory. Specifically, files with restrictive permissions (e.g., 600) can be made world-readable (755), potentially exposing sensitive information. The issue affects Unix-like operating systems and does not impact Windows. There is no indication of remote code execution or privilege escalation beyond file permission modification. The CVSS 4.0 score is 6.7 (medium severity), reflecting local attack vector with user interaction and high impact on confidentiality due to permission changes.

Summary

The vulnerability in pnpm@9 occurs when processing the 'directories.bin' field in a package's manifest. The code uses path.join() to resolve the bin directory path but does not validate that the resulting path remains a subdirectory of the package root. A malicious package can exploit this by specifying a relative path that escapes the package directory, leading pnpm to modify file permissions on arbitrary files outside the intended directory. This affects Unix/Linux/macOS systems only, as the code path is gated on executable shebang support. The issue is due to missing isSubdir() validation on 'directories.bin' paths, unlike other similar code paths. The impact is a supply-chain attack vector where file permissions on sensitive files can be escalated from restrictive (600) to world-readable (755).

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 4 Nov 2026, 01:45 UTC

Technical details

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