Your RSA-2048 keys break in 2030. Find every one of them before attackers do.
📦
📦 npm
Not in CISA KEV
HIGH severity

GHSA-5wx6-mg75-v57r

HIGHFix: pnpm/pnpm@bf1b731

GHSA-5wx6-mg75-v57r is a high-severity (CVSS 7.5) CWE-346 vulnerability in pnpm. O3 Security confirms whether GHSA-5wx6-mg75-v57r is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.

pnpm: Manifest identity spoof satisfies allowBuilds and runs attacker lifecycle

Also known asCVE-2026-55487
Published
Jun 26, 2026
Updated
Jun 26, 2026
Affected
2 pkgs
Patched
2 / 2
Exploits
None indexed
Exploitation data as of Aug 11, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

Proof-of-concept exploit code exists

  • CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
  • A successful exploit gives an attacker total control of the affected component, not partial access.

Exploitation and automatability from CISA’s SSVC triage for GHSA-5wx6-mg75-v57r.

EPSS Exploitation Probability

via FIRST.org ↗
0.2%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs6th percentile — riskier than 6% of all scored CVEsHighest risk
0.00%0.22%0.44%0.66%0.1%0.2%0.2%Jul 26Aug 26Aug 26

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.

How urgent is this, really

GHSA-5wx6-mg75-v57r plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.

Where this sits among everything scored

Of 358,265 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.

Real-World Exposure

2 pkgs affected

How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.

369other npm packages depend on this — each one inherits the vulnerability until it's patched upstream
pnpmnpm
153.0Mdownloads / week

Description

Summary

Keep build approval for opaque dependency sources byte-exact for GHSA-5wx6-mg75-v57r / CAND-PNPM-123.

Merged upstream commit bf1b731ee6 fixed the original name-only approval bypass by making build policy consume the resolved dependency identity. One collision remained: 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.

Security boundary

  • Registry dependency identities still normalize legitimate peer suffixes and retain patch hashes.
  • Git, URL, tarball, file, directory, and otherwise opaque identities must match the complete resolved locator byte for byte.
  • Explicit denials use the same normalization as approvals.
  • Ignored-build output preserves the exact opaque identity, so the key pnpm asks a user to approve is the key policy later checks.
  • TypeScript pnpm and pacquet implement the same distinction between registry and opaque identities.

Exploit replay

  • With allowBuilds approving foo@https://host/pkg.tgz, the upstream implementation also accepted foo@https://host/pkg.tgz(evil) because both passed through peer-suffix removal.
  • An independent review found a second Rust-only form: foo@https://host/[email protected](good) and foo@https://host/[email protected](evil) collided because the parser selected the final @ and misclassified the opaque URL as a registry package.
  • A final review found the same parser hazard in source-only locators ending in a semver-looking tail: approval for https://host/[email protected] could collapse https://host/[email protected](evil).
  • The final patch rejects all three collision forms, applies the same exactness to deny rules, accepts exact opaque keys as positive controls, and continues to accept registry packages approved without their peer suffixes.

Files changed

  • building/policy/src/index.ts and building/policy/test/index.ts normalize only parsed registry identities and retain exact opaque keys.
  • pacquet/crates/package-manager/src/build_modules.rs passes snapshot identities to policy, matches TypeScript package-separator parsing, and preserves opaque locators.
  • pacquet/crates/package-manager/src/build_modules/tests.rs covers exact approval and denial, all three collision forms, ignored-build output, and registry peer compatibility.
  • .changeset/quiet-opaque-build-identities.md records patch releases for @pnpm/building.policy and pnpm.

Commands run

$ jest building/policy/test/index.ts --runInBand
16 passed
$ cargo test -p pacquet-package-manager build_modules::tests -- --nocapture
49 passed
$ cargo fmt --all -- --check
PASS
$ git diff --check 84bb4b1a046f3a659de1c9aab1d45dcf814124ce...HEAD
PASS

Validation

  • The TypeScript policy suite passed all 16 tests.
  • The final pacquet build-policy suite passed all 49 tests.
  • The new Rust regression reproduced the extra-@ collision before the additive fix and passed afterward.
  • Exact opaque approval and denial, source-only semver-tail collision rejection, registry peer normalization, and ignored-build reporting all have paired tests.
  • ESLint passed on the changed TypeScript source and test files.
  • Rust formatting and diff checks passed; the branch is clean and consists of three focused security commits plus additive merges of upstream through 84bb4b1a046f3a659de1c9aab1d45dcf814124ce.
  • The focused TypeScript suite and ESLint ran directly through the installed harness. The isolated project build cannot resolve workspace packages without a local install, and the configured registry gateway returns HTTP 403 while fetching @pnpm/[email protected]; no candidate-focused test failed.

Patches

10.34.2: https://github.com/pnpm/pnpm/commit/14bceb1e0b2a71f4f670774db261feb03f38ec23 11.5.3: https://github.com/pnpm/pnpm/commit/bf1b731ee6c0ea98709e671ff0f46bf654480ab8

Compatibility

Registry package approvals keep their existing form. Opaque dependencies that were approved through a normalized parenthesized variant must now use the exact key shown in pnpm's ignored-build output. This is the intended trust-boundary change; no package-resolution or artifact format changes.

CI note

GitHub intentionally does not run status checks on temporary private-fork pull requests. The complete policy suites, formatting, and diff checks above are the applicable validation: https://docs.github.com/code-security/security-advisories/collaborating-in-a-temporary-private-fork-to-resolve-a-security-vulnerability


Written by an agent (Codex, GPT-5).

Affected Packages

2 total 2 fixed
EcosystemPackageVulnerable rangeFix
📦npmpnpmall versions10.34.2
📦npmpnpm11.0.0&&< 11.5.311.5.3

Detection & mitigation playbook

Open-source dependency
  1. Detect

    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.

  2. Fix

    Update pnpm to 10.34.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-5wx6-mg75-v57r is resolved across your whole dependency graph.

  3. 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.

  4. How O3 protects you

    O3 pinpoints whether GHSA-5wx6-mg75-v57r 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-5wx6-mg75-v57r. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

## Summary Keep build approval for opaque dependency sources byte-exact for GHSA-5wx6-mg75-v57r / CAND-PNPM-123. Merged upstream commit `bf1b731ee6` fixed the original name-only approval bypass by making build policy consume the resolved dependency identity. One collision remained: 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. ## Security boundary - Registry dependency ident
O3 Security · Impact-Aware SCA

Is GHSA-5wx6-mg75-v57r in your dependencies?

O3 detects GHSA-5wx6-mg75-v57r across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

GHSA-5wx6-mg75-v57r: pnpm (High 7.5) | O3 Security