Cyber Resilience

CWE · MITRE source

CWE-807Reliance on Untrusted Inputs in a Security Decision

Abstraction: Base · CVEs in our corpus: 93

The product uses a protection mechanism that relies on the existence or values of an input, but the input can be modified by an untrusted actor in a way that bypasses the protection mechanism.

Developers may assume that inputs such as cookies, environment variables, and hidden form fields cannot be modified. However, an attacker could change these inputs using customized clients or other attacks. This change might not be detected. When security decisions such as authentication and authorization are made based on the values of these inputs, attackers can bypass the security of the software. Without sufficient encryption, integrity checking, or other mechanism, any input that originates from an outsider cannot be trusted.

Last updated: 20 August 2026 13:14 UTC

OWASP Top 10 for Web (2025)

This weakness contributes to A06:2025 Insecure Design.

Control responseHuman-reviewed

Answering this weakness across the control lifecycle, from our framework cross-walks.

Prevent
Stop it (NIST 800-53 / CSF Protect)
  • PT-8 Computer Matching Requirements
  • SC-16 Transmission of Security and Privacy Attributes
  • SI-9 Information Input Restrictions
  • PR.AA-01
Detect
Catch it (CSF Detect / Respond)

Harden
Shrink the surface (DISA STIG)
  • 1 hardening rule · 1 OS baseline
Validate
Prove the fix (OWASP ASVS)

NIST 800-53 r5 controls that address this weakness (3)AI-assisted

Control Title Family Why it addresses this CWE
PT-8Computer Matching RequirementsPTPrevents reliance on untrusted matching results for security-relevant decisions by enforcing verification and contest procedures.
SC-16Transmission of Security and Privacy AttributesSCProviding authoritative attributes with the data reduces the need for security decisions to rely on untrusted external inputs.
SI-9Information Input RestrictionsSIReduces reliance on untrusted inputs by ensuring only authorized sources may supply data.

Top CVEs of this weakness type, ranked by Risk Priority

CVE Risk CVSS EPSS Published
CVE-2026-21509 KEV 8.57.80.72152026-01-26
CVE-2026-21514 KEV8.57.80.01522026-02-10
CVE-2026-34486 KEV 8.57.50.82932026-04-09
CVE-2025-49827 7.69.80.01402025-07-15
CVE-2026-24120 7.59.80.00902026-05-04
CVE-2025-12487 7.49.80.00852025-11-06
CVE-2025-12488 7.49.80.00852025-11-06
CVE-2023-45128 7.310.00.00312023-10-16
CVE-2025-139267.39.80.00442026-04-09
CVE-2026-648277.39.80.00432026-08-03
CVE-2025-665707.210.00.00332025-12-05
CVE-2026-329757.29.80.00342026-03-29
CVE-2026-48491 7.210.00.00282026-06-23
CVE-2026-44649 7.19.80.00222026-05-29
CVE-2024-13974 6.98.10.06702025-07-21
CVE-2021-31999 6.88.80.01052021-07-15
CVE-2021-41129 6.58.10.01752021-10-06
CVE-2024-29039 6.59.00.00982024-06-28
CVE-2026-330686.58.80.00342026-03-20
CVE-2025-1126 6.49.30.00252025-02-11
CVE-2021-36777 6.38.10.00912022-03-09
CVE-2026-31892 6.18.10.00412026-03-11
CVE-2024-28824 6.08.80.00182024-03-22
CVE-2026-43935 6.08.10.00302026-05-26
CVE-2026-9561 6.08.20.00192026-07-14