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Fencer Vulns
high 7.5

CVE-2026-55487 json

pnpm: manifest identity spoof satisfies allowBuilds and runs attacker lifecycle

published 2026-06-25 4 mo ago modified 2026-06-29 4 mo ago also GHSA-5wx6-mg75-v57r , EUVD-2026-39481

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 7%
public exploits
0
none known

Summary

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.

Patch / fix

  • npm pnpm 10.34.2, 11.5.3
  • pnpm pnpm 10.34.2, 11.5.3

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-55487 updated cvss 7.5

pnpm: pnpm: Supply chain compromise via manipulated package source strings

  • Red Hat AMQ Broker 7 pnpm
    not affected: vulnerable code not present
  • Red Hat Build of Keycloak pnpm
    not affected: component not present
  • Red Hat JBoss Enterprise Application Platform 8 pnpm Red Hat JBoss Enterprise Application Platform Expansion Pack pnpm
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
total
Assessed
4 mo ago

Exploit prediction

0.18% chance of exploitation in the next 30 days, higher than 7% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/pnpm/pnpm/security/advisories/GHSA-5wx6-mg75-v57r referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
NVD 3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
GitHub 3.1 7.5 CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H

Affected packages

ecosystem package affected fixed in
npm pnpm
<10.34.2
>=11.0.0, <11.5.3
10.34.2
11.5.3

Affected products

  • pnpm pnpm

Classification

Weakness
  • CWE-346 Origin Validation Error
  • CWE-693 Protection Mechanism Failure
  • CWE-829 Inclusion of Functionality from Untrusted Control Sphere

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.