Cyber Resilience

CVE-2026-55487

Pnpm ≤ 10.34.2

Public PoC
Published
25 June 2026
Modified
29 June 2026
Patch / advisory
View advisory
CVSS Score v3.1 7.5
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS Score 0.0016 6th percentile
Risk Priority 53 floored blend · peak EPSS

Summary

CVE-2026-55487 is a high-severity Origin Validation Error (CWE-346) vulnerability in Pnpm Pnpm. Its CVSS base score is 7.5 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Supply Chain Compromise (T1195); ranked at the 6th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified map to AC-3 (Access Enforcement) and AC-4 (Information Flow Enforcement) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

A06:2025 Insecure DesignA07:2025 Authentication FailuresA08:2025 Software or Data Integrity Failures

EU & UK References

Vulnerability Data

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…

more

locator normalized to the same value. This vulnerability is fixed in 10.34.2 and 11.5.3.

CWE(s)
CWE-346CWE-693CWE-829

Related Threats

MITRE ATT&CK Enterprise Techniques

T1195 Supply Chain Compromise Initial Access
Adversaries may manipulate products or product delivery mechanisms prior to receipt by a final consumer for the purpose of data or system compromise.
attack.mitre.org →
T1548 Abuse Elevation Control Mechanism Privilege Escalation
Adversaries may circumvent mechanisms designed to control privilege elevation to gain higher-level permissions.
attack.mitre.org →
T1553 Subvert Trust Controls Defense Impairment
Adversaries may undermine security controls that will either warn users of untrusted activity or prevent execution of untrusted programs.
attack.mitre.org →
T1553.005 Mark-of-the-Web Bypass Defense Impairment
Adversaries may abuse specific file formats to subvert Mark-of-the-Web (MOTW) controls.
attack.mitre.org →
T1557.003 DHCP Spoofing Credential Access
Adversaries may redirect network traffic to adversary-owned systems by spoofing Dynamic Host Configuration Protocol (DHCP) traffic and acting as a malicious DHCP server on the victim network.
attack.mitre.org →
T1600 Weaken Encryption Defense Impairment
Adversaries may compromise a network device’s encryption capability in order to bypass encryption that would otherwise protect data communications.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2025-69264Same product: Pnpm Pnpm
CVE-2026-55698Same product: Pnpm Pnpm
CVE-2026-55697Same product: Pnpm Pnpm
CVE-2026-50573Same product: Pnpm Pnpm
CVE-2026-24131Same product: Pnpm Pnpm
CVE-2026-50021Same product: Pnpm Pnpm
CVE-2023-37478Same product: Pnpm Pnpm
CVE-2026-55180Same product: Pnpm Pnpm
CVE-2026-50017Same product: Pnpm Pnpm
CVE-2026-59196Same product: Pnpm Pnpm

Affected Assets

pnpm
pnpm
≤ 10.34.2 · 11.0.0 — 11.5.3

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)
  • 17 hardening rules · 10 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V14.2.3
  • V6.3.3
  • V6.6.3
  • V10.2.2

Mitigating Controls (NIST 800-53 r5) AI

AC-3 Access Enforcement good match

AC-3 directly requires enforcement of access authorizations via the protection mechanism itself.

AC-4 Information Flow Enforcement good match

AC-4 mandates use of information flow enforcement mechanisms to control data movement.

SC-2 Separation of System and User Functionality good match

SC-2 requires separation of user and system functionality as a protection mechanism.

SC-28 Protection of Information at Rest good match

SC-28 requires protection mechanisms for information at rest.

SC-3 Security Function Isolation good match

SC-3 requires isolation of security functions from non-security functions.

SC-7 Boundary Protection good match

SC-7 requires boundary protection mechanisms to monitor and control external communications.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

ID.RA-09 full match
prevents

Pre-acquisition integrity/authenticity checks directly prevent inclusion of untrusted code.

GV.SC-01 mostly match
prevents

Supply-chain program directly governs inclusion of third-party executable code.

GV.SC-05 mostly match
prevents

Contractual requirements can mandate trusted sources and integrity checks for included functionality.

GV.SC-07 mostly match
prevents

Supplier risk assessment explicitly covers risks from their products and libraries.

ID.RA-10 mostly match
prevents

Critical-supplier assessment reduces risk of importing executable functionality from untrusted parties.

PR.AA-03 mostly match
prevents

Authentication directly verifies the source of users/services/hardware, mitigating origin validation failures.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.5.21 Managing information security in the ICT supply chain mostly match
prevents

By requiring suppliers to propagate security requirements and to disclose component provenance, the control limits the inclusion of functionality obtained from untrusted third-party sources without oversight.

A.5.36 Compliance with policies, rules and standards for information security partial match
finds

Systematic verification that security mechanisms operate according to defined standards reduces the likelihood that protection mechanisms are bypassed or disabled.

A.8.20 Networks security partial match
mitigates

Network security controls enforce origin validation at network boundaries.

A.8.21 Security of network services partial match
mitigates

Security of network services includes validating the authenticity of service endpoints.

A.8.22 Segregation of networks partial match
mitigates

Network segregation reduces exposure but does not directly validate origins.

A.8.26 Application security requirements partial match
prevents

Application security requirements explicitly call for origin validation of inputs and communications.

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).

Oracle Linux 8 (6 rules)
  • V-248524 OL 8 must implement NIST FIPS-validated cryptography for the following: To provision digital signatures, to generate cryptographic hashes, and to protect data requiring data-at-rest protections in accordance with applicable federal laws, Executive Orders, directives, policies, regulations, and standards. prevents CWE-693
  • V-248525 All OL 8 local disk partitions must implement cryptographic mechanisms to prevent unauthorized disclosure or modification of all information that requires at-rest protection. prevents CWE-693
  • V-248574 YUM must be configured to prevent the installation of patches, service packs, device drivers, or OL 8 system components that have not been digitally signed using a certificate that is recognized and approved by the organization. prevents CWE-346
Oracle Linux 9 (1 rule)
  • V-271847 OL 9 must be configured so that executable search paths within the initialization files of all local interactive users must only contain paths that resolve to the system default or the users home directory. prevents CWE-829
RHEL 7 (1 rule)
  • V-204477 The Red Hat Enterprise Linux operating system must be configured so that all local interactive user initialization files executable search paths contain only paths that resolve to the users home directory. prevents CWE-829
RHEL 8 (1 rule)
  • V-230317 Executable search paths within the initialization files of all local interactive RHEL 8 users must only contain paths that resolve to the system default or the users home directory. prevents CWE-829
RHEL 9 (1 rule)
  • V-258050 Executable search paths within the initialization files of all local interactive RHEL 9 users must only contain paths that resolve to the system default or the users home directory. prevents CWE-829
Windows 10 (3 rules)
  • V-220865 The Windows Remote Management (WinRM) service must not use Basic authentication. prevents CWE-693
  • V-220737 Administrative accounts must not be used with applications that access the Internet, such as web browsers, or with potential Internet sources, such as email. prevents CWE-829
  • V-220812 Credential Guard must be running on Windows 10 domain-joined systems. prevents CWE-693
Windows 11 (1 rule)
  • V-253418 The Windows Remote Management (WinRM) service must not use Basic authentication. prevents CWE-693
Windows Server 2016 (1 rule)
  • V-225012 Windows Server 2016 must be running Credential Guard on domain-joined member servers. prevents CWE-693
Windows Server 2019 (1 rule)
  • V-205907 Windows Server 2019 must be running Credential Guard on domain-joined member servers. prevents CWE-693
Windows Server 2022 (1 rule)
  • V-254441 Windows Server 2022 must be running Credential Guard on domain-joined member servers. prevents CWE-693

References