CVE-2026-17861
Raw vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:HSummary
CVE-2026-17861 is a high-severity Improper Input Validation (CWE-20) vulnerability in Chromium (inferred from references). Its CVSS base score is 7.8 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 0.4th 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-6 (Least Privilege) and SI-10 (Information Input Validation) — see the control section below for these in your framework.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-50610
Vulnerability Data
Insufficient validation of untrusted input in Updater in Google Chrome prior to 151.0.7922.72 allowed a local attacker to perform OS-level privilege escalation via a malicious file. (Chromium security severity: Medium)
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Local privilege escalation via malicious file due to insufficient input validation in privileged Chrome Updater component directly enables exploitation for privilege escalation.
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
- 6 hardening rules · 3 OS baselines
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Mitigating Controls (NIST 800-53 r5) AI
Directly requires validation of untrusted input, which is the root cause of the malicious file being processed by the Chrome Updater.
Enforces least privilege on the updater process so that a successful malicious-file exploit cannot achieve OS-level privilege escalation.
Requires integrity verification of files and software before processing, limiting the ability of an attacker-supplied malicious file to be acted upon.
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.
Secure SDLC practices directly require and enforce input validation during development.
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.
Testing against a defined set of requirements and using code review plus vulnerability scanning forces validation of inputs and handling of unanticipated conditions, reducing the chance that malformed data will be accepted.
Secure-coding guidelines and mandatory security testing (including code scans) compel developers to validate and sanitize inputs at design and implementation time, lowering the incidence of malformed or malicious data reaching downstream components.
Mandating input controls that include integrity checks and input validation ensures that untrusted data is examined before use, blocking the root cause of many injection and malformed-data weaknesses.
Security-by-design principles explicitly call for data validation and sanitization at every layer, reducing the chance that malformed or malicious input will be processed without scrutiny.
Requiring language-specific secure coding standards, peer review, SAST and documented mitigation of common programming errors forces validation of all inputs before they are trusted.
Regular automated validation of system software and data content, combined with scanning of all inbound files, enforces input validation at the boundary before untrusted content is processed.