Quick answer
Direct answer
Risk scores
| CVSS metric | What it means |
|---|---|
| Attack vector (AV:N) | Network: reachable remotely |
| Attack complexity (AC:H) | High complexity |
| Privileges required (PR:N) | No privileges required |
| User interaction (UI:R) | A user must take an action |
| Scope (S:U) | Scope unchanged |
| Confidentiality (C:H) | High confidentiality impact |
| Integrity (I:H) | High integrity impact |
| Availability (A:H) | High availability impact |
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
About Pnpm
CVE-2026-55487 affects Pnpm, a product from Pnpm. Before acting, confirm where Pnpm runs in your estate, who owns it and whether it is reachable from the internet, because exposure decides real risk more than the score alone.
What the flaw is
In plain terms: pnpm is a package manager. Prior to 10.34.2 and 11.5.3, the generic peer-suffix normalizer also stripped parenthesized text from git, URL, tarball, file, and other opaque locators. Approval for one source string could therefore authorize a different attacker-controlled source whose locator normalized to the same value. This vulnerability is fixed in 10.34.2 and 11.5.3.
Based on its CVSS vector, the flaw can be reached over the network, needs no login, and relies on a user taking an action. Apply the vendor fix and confirm exposure on internet facing and business critical assets first.
Affected versions and timeline
| Field | Detail |
|---|---|
| Product | Pnpm |
| Affected versions | Pnpm before 10.34.2; Pnpm from 11.0.0 before 11.5.3 |
| Published | Jun 25, 2026 |
| Last modified | Jun 29, 2026 |
| Added to CISA KEV | Not listed |
| Assigning CNA | security-advisories@github.com |
How to detect it
- Inventory every instance of Pnpm and record the running version against the affected range above.
- Check external attack surface scans for internet facing instances of the component.
- Review logs on affected systems for unusual requests, errors or new processes around the vulnerable function.
- Confirm with an authenticated vulnerability scan once your scanner has a check for this CVE.
How to fix it
- Apply the fixed version of Pnpm named in the vendor advisory.
- If patching must wait, restrict network access to the affected service and put it behind authentication or a web application firewall rule.
- Rescan after the change to prove the exposure is gone, then close the ticket.
CTEM action plan
| CTEM stage | What to do for this CVE |
|---|---|
| Scope | Add every business service that depends on Pnpm to the current CTEM cycle. |
| Discover | Find all instances, including shadow and cloud deployments, and record versions and exposure. |
| Prioritize | Rank using EPSS and CVSS together with asset exposure and business impact. |
| Validate | Confirm the flaw is reachable and exploitable in your environment and that compensating controls work. |
| Mobilize | Assign the fix to the asset owner with a due date matched to the priority, then verify closure. |
CWE References
Technical References
Frequently asked questions
Related CVEs
pnpm is a package manager. Prior to 10.34.2 and 11.5.3, pnpm can install configDependencies declared in pnpm-workspace.yaml before command dispatch. Before the patch, a repository could declare pacquet or @pnpm/pacquet as a config dependency and pnpm treated that repository-controlled dependency as an install-engine opt-in. During install, pnpm resolved a platform-specific @pacquet/<platform>-<arch>/pacquet binary from node_modules/.pnpm-config/<packageName> and spawned it as the developer or CI user. This vulnerability is fixed in 10.34.2 and 11.5.3.
pnpm is a package manager. Versions 6.25.0 through 10.26.2 have a Command Injection vulnerability when using environment variable substitution in .npmrc configuration files with tokenHelper settings. An attacker who can control environment variables during pnpm operations could achieve Remote Code Execution (RCE) in build environments. This issue is fixed in version 10.27.0.
pnpm is a package manager. Versions 10.0.0 through 10.25 allow git-hosted dependencies to execute arbitrary code during pnpm install, circumventing the v10 security feature "Dependency lifecycle scripts execution disabled by default". While pnpm v10 blocks postinstall scripts via the onlyBuiltDependencies mechanism, git dependencies can still execute prepare, prepublish, and prepack scripts during the fetch phase, enabling remote code execution without user consent or approval. This issue is fixed in version 10.26.0.
pnpm is a package manager. Versions 10.26.2 and below store HTTP tarball dependencies (and git-hosted tarballs) in the lockfile without integrity hashes. This allows the remote server to serve different content on each install, even when a lockfile is committed. An attacker who publishes a package with an HTTP tarball dependency can serve different code to different users or CI/CD environments. The attack requires the victim to install a package that has an HTTP/git tarball in its dependency tree. The victim's lockfile provides no protection. This issue is fixed in version 10.26.0.
Site isolation issue in the DOM: Navigation component. This vulnerability was fixed in Firefox 155, Firefox ESR 153.2, Thunderbird 155, and Thunderbird 153.2.
Same-origin policy bypass in the Networking: JAR component. This vulnerability was fixed in Firefox 148, Firefox ESR 140.8, Thunderbird 148, and Thunderbird 140.8.
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