Cyber Resilience

CVE-2026-75873

Published
30 September 2026
Modified
30 September 2026
CVSS Score v3.1 9.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0057 45th percentile
Risk Priority 72 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2026-75873 is a critical-severity Unrestricted Upload of File with Dangerous Type (CWE-434) vulnerability. Its CVSS base score is 9.8 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Command and Scripting Interpreter (T1059); ranked at the 45th 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 CM-7 (Least Functionality) and SC-18 (Mobile Code) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

A06:2025 Insecure Design

EU & UK References

Vulnerability Data

The Zella Theme WordPress theme before 2.6.3 does not perform any capability or nonce check on one of its font upload actions, which is available to unauthenticated users, allowing them to upload arbitrary files, including PHP ones, and achieve remote…

more

code execution.

CWE(s)
CWE-434

Related Threats

MITRE ATT&CK Enterprise Techniques

T1059 Command and Scripting Interpreter Execution
Adversaries may abuse command and script interpreters to execute commands, scripts, or binaries.
attack.mitre.org →
T1105 Ingress Tool Transfer Command And Control
Adversaries may transfer tools or other files from an external system into a compromised environment.
attack.mitre.org →
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
T1505 Server Software Component Persistence
Adversaries may abuse legitimate extensible development features of servers to establish persistent access to systems.
attack.mitre.org →
T1505.003 Web Shell Persistence
Adversaries may backdoor web servers with web shells to establish persistent access to systems.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2024-1116Shared CWE-434
CVE-2024-37420Shared CWE-434
CVE-2020-37227Shared CWE-434
CVE-2023-51928Shared CWE-434
CVE-2024-51788Shared CWE-434
CVE-2023-44763Shared CWE-434
CVE-2025-49387Shared CWE-434
CVE-2025-6802Shared CWE-434
CVE-2026-36669Shared CWE-434
CVE-2024-42375Shared CWE-434

Affected Assets

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V5.1.1

Mitigating Controls (NIST 800-53 r5) AI

CM-7 Least Functionality partial match

Least functionality restricts the file types and automatic processing capabilities the system will accept.

SC-18 Mobile Code partial match

Mobile-code controls define, authorize, and block unacceptable uploaded code before automatic processing occurs.

SI-3 Malicious Code Protection partial match

Malicious-code protection at entry points blocks dangerous file types from being accepted and executed.

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-01 partial match
prevents

Hardened configuration baselines can enforce allowed file types and processing rules.

PR.PS-05 partial match
prevents

Restricting execution of unauthorized software directly blocks dangerous uploaded files from running.

PR.PS-06 partial match
prevents

Secure development practices include input validation and file-type restrictions that prevent this weakness.

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.5.14 Information transfer partial match
removes
A.5.15 Access control partial match
removes
A.5.16 Identity management partial match
removes
A.5.17 Authentication information partial match
removes
A.5.18 Access rights partial match
removes
A.5.25 Assessment and decision on information security events partial match
removes

References