What is the CVSS score of CVE-2026-55487?

CVE-2026-55487 has a CVSS 3.1 base score of 8.8 (High). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H. EPSS exploitation probability: 0.1%.

Which versions of pnpm are affected by CVE-2026-55487?

CVE-2026-55487 affects pnpm package managers before version 10.34.2 and 11.0.0-11.5.2, enabling attackers to bypass build-script approval controls and inject malicious code into the dependency…. A patch is available.

How to fix or mitigate CVE-2026-55487?

Within 24 hours: Scan all build systems, development environments, and CI/CD pipelines to identify pnpm installations and document their current versions. Within 7 days: Upgrade to pnpm 10.34.2 or later (v10 series) and the latest available v11 release; rebuild all application artifacts and dependencies using the patched version. Within 30 days: Audit all build outputs and released binaries from the 90 days before patching for signs of malicious code injection; rotate any secrets or credentials exposed during affected builds.

pnpm CVE-2026-55487

EUVD-2026-39481 HIGH

Origin Validation Error (CWE-346)

2026-06-25 GitHub_M

GHSA-5wx6-mg75-v57r

Information Disclosure Red Hat Pnpm

8.8

CVSS 3.1 · NVD

Severity by source

Vendor (GitHub_M) PRIMARY

HIGH

qualitative

NVD

8.8 HIGH

AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

vuln.today AI

8.8 HIGH

Network-delivered dependency, no attacker privileges, but a victim must approve a build (UI:R); successful lifecycle execution yields total host compromise so C/I/A all High.

3.1 AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

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

Red Hat

7.5 HIGH

qualitative

Primary rating from Vendor (GitHub_M).

CVSS VectorNVD

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

Source Code Evidence Fetched

Jun 29, 2026 - 21:33 vuln.today

Analysis Updated

Jun 29, 2026 - 21:33 vuln.today

v3 (cvss_changed)

Analysis Updated

Jun 29, 2026 - 21:32 vuln.today

v2 (cvss_changed)

Re-analysis Queued

Jun 29, 2026 - 21:22 vuln.today

cvss_changed

CVSS changed

Jun 29, 2026 - 21:22 NVD

7.5 (HIGH) 8.8 (HIGH)

Patch available

Jun 25, 2026 - 19:17 EUVD

Analysis Generated

Jun 25, 2026 - 18:15 vuln.today

DescriptionNVD

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.

AnalysisAI

Build-script approval bypass in the pnpm package manager (versions before 10.34.2, and 11.0.0 through 11.5.2) lets an attacker-controlled dependency source run lifecycle scripts that a user only approved for a different, legitimate source. The generic peer-suffix normalizer stripped parenthesized text from opaque locators (git, URL, tarball, file), so two distinct sources could normalize to the same allowBuilds key - meaning approval of foo@https://host/pkg.tgz also authorized foo@https://host/pkg.tgz(evil). Publicly available exploit code exists (SSVC: poc) and technical impact is total, though EPSS is low at 0.11% and it is not in CISA KEV.

Technical ContextAI

pnpm gates execution of dependency lifecycle (build) scripts behind an explicit allowBuilds approval policy keyed on a dependency's resolved identity. For registry packages, that identity legitimately normalizes peer-dependency suffixes (the parenthesized tail) so a package approved without its peer suffix still matches. The defect is a CWE-346 Origin Validation Error: the same generic normalizer was applied to opaque, non-registry locators (git, URL, tarball, file, directory), incorrectly stripping parenthesized content from sources whose identity must be byte-exact. CPE cpe:2.3:a:pnpm:pnpm confirms the affected component is pnpm itself. The advisory documents three collision forms - the parenthesized-suffix strip, a Rust-only final-@ misclassification (foo@https://host/pkg@1.0.0(good) vs (evil)), and a semver-looking source-only tail (https://host/pkg@1.0.0 collapsing (evil)) - all rooted in treating opaque identities like registry identities.

RemediationAI

Vendor-released patch: upgrade to pnpm 10.34.2 (for the 10.x line) or 11.5.3 (for the 11.x line), which reject all three normalization-collision forms and enforce byte-exact matching for opaque locators while preserving legitimate registry peer-suffix normalization. The fix is implemented in commit bf1b731ee6c0ea98709e671ff0f46bf654480ab8 and described in advisory https://github.com/pnpm/pnpm/security/advisories/GHSA-5wx6-mg75-v57r. If you cannot upgrade immediately, the most effective compensating control is to disable automatic lifecycle-script execution entirely (for example pin onlyBuiltDependencies to an empty/explicit allowlist or run installs with scripts disabled), accepting the trade-off that packages genuinely needing native builds will not compile until run manually; additionally, prefer registry-pinned dependencies over git/URL/tarball/file locators and audit any opaque sources in your lockfile, since those are the only locator types this bug affects.