Cyber Resilience

CVE-2026-4135

Published
15 April 2026
Modified
17 April 2026
CVSS Score v4 5.2
Click a component to see what it means
Raw vectorCVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:P/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0012 2th percentile
Risk Priority 35 floored blend · peak EPSS

Summary

CVE-2026-4135 is a medium-severity Link Following (CWE-59) vulnerability in Lenovo Software Fix (inferred from references). Its CVSS base score is 5.2 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 2th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to AC-3 (Access Enforcement) and AC-6 (Least Privilege) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

A01:2025 Broken Access Control

EU & UK References

Vulnerability Data

During an internal security assessment, a potential vulnerability was discovered in Lenovo Software Fix, that during installation could allow a local authenticated user to perform an arbitrary file write with elevated privileges.

CWE(s)
CWE-59

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
attack.mitre.org →
Why these techniques?

Arbitrary file write via link following (CWE-59) during privileged installation directly enables local privilege escalation.

Confidence: MEDIUM · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2025-63945Shared CWE-59
CVE-2026-2627Shared CWE-59
CVE-2026-15684Shared CWE-59
CVE-2025-15310Shared CWE-59
CVE-2026-49791Shared CWE-59
CVE-2026-33694Shared CWE-59
CVE-2026-39819Shared CWE-59
CVE-2026-11837Shared CWE-59
CVE-2026-50469Shared CWE-59
CVE-2025-49739Shared CWE-59

Affected Assets

Lenovo
Software Fix
inferred from references and description; NVD did not file a CPE for this CVE

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
  • AC-6 Least Privilege
  • AC-3 Access Enforcement
  • CM-5 Access Restrictions for Change
Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V15.4.2

Mitigating Controls (NIST 800-53 r5) AI

AC-6 Least Privilege good match
prevent

Limits privileges of the Lenovo Software Fix installer process so a local authenticated user cannot obtain elevated rights for arbitrary file writes.

AC-3 Access Enforcement good match
prevent

Enforces access-control checks on file operations during installation, blocking link-following writes to unintended privileged locations.

CM-5 Access Restrictions for Change partial match
prevent

Restricts which principals may perform configuration changes or file writes during software installation or updates.

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.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly require code to validate paths and avoid unsafe link following.

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.8.29 Security testing in development and acceptance mostly match
detects

Security testing can detect link-following flaws before release.

A.8.25 Secure development life cycle partial match
prevents

Secure SDLC practices can mandate link-resolution checks and canonicalization before file access.

A.8.26 Application security requirements partial match
prevents

Application security requirements can explicitly require safe handling of symbolic links and path traversal.

A.8.27 Secure system architecture and engineering principles partial match
prevents

Secure architecture principles include input validation and safe file-access design patterns.

A.8.28 Secure coding partial match
prevents

Secure coding standards directly address canonicalization and symlink attacks during implementation.

A.8.3 Information access restriction none match
none

Access-control rules can limit which files are reachable, reducing exposure to malicious links.

References