CVE-2026-26101

HighLPE

Published: 20 February 2026

Published

20 February 2026

Modified

27 February 2026

KEV Added

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Patch

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CVSS Score 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS Score 0.0002 4.8th percentile

Risk Priority 16 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-26101 is a high-severity Incorrect Permission Assignment for Critical Resource (CWE-732) vulnerability in Owlcyberdefense Opds-Talon. Its CVSS base score is 7.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique File System Permissions Weakness (T1044); ranked at the 4.8th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified are NIST 800-53 AC-3 (Access Enforcement) and AC-6 (Least Privilege).

Threat & Defense at a Glance

What attackers do: exploitation maps to File System Permissions Weakness (T1044) and 1 other technique. What defenders deploy: see the NIST 800-53 controls recommended below.

Threat & Defense Details

Mitigating Controls (NIST 800-53 r5)AI

AC-6 Least Privilege good match

prevent

Employs least privilege to prevent low-privilege local attackers from manipulating critical resources via crafted network requests.

AC-3 Access Enforcement good match

prevent

Enforces approved authorizations on critical resources, directly countering incorrect permission assignments that enable file manipulation.

CM-6 Configuration Settings good match

prevent

Mandates secure configuration settings for critical resources, including proper file permissions, to mitigate improper assignments in Owl opds.

MITRE ATT&CK Enterprise TechniquesAI

T1044 File System Permissions Weakness Persistence

Processes may automatically execute specific binaries as part of their functionality or to perform other actions.

attack.mitre.org →

T1068 Exploitation for Privilege Escalation Privilege Escalation

Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.

attack.mitre.org →

Why these techniques?

Incorrect permission assignment (CWE-732) on a critical resource directly enables abuse of file system permissions weakness (T1044) by a low-privileged local attacker; the resulting file manipulation with high C/I/A impact constitutes exploitation of a software vulnerability for privilege escalation (T1068).

Confidence: HIGH · MITRE ATT&CK Enterprise v18.1

NVD Description

Incorrect Permission Assignment for Critical Resource in Owl opds 2.2.0.4 allows File Manipulation via a crafted network request.

Deeper analysisAI

CVE-2026-26101, published on 2026-02-20, is an Incorrect Permission Assignment for Critical Resource vulnerability (CWE-732) in Owl opds version 2.2.0.4. This flaw enables file manipulation via a crafted network request due to improper permissions on a critical resource. The CVSS v3.1 base score is 7.8 (AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H), indicating high severity with local access vector, low attack complexity, and low privileges required.

A local attacker with low privileges (PR:L) can exploit this vulnerability without user interaction by sending a crafted network request. Successful exploitation allows file manipulation on critical resources, resulting in high impacts to confidentiality, integrity, and availability (C:H/I:H/A:H).

Mitigation details are provided in the advisory at https://www.nozominetworks.com/labs/vulnerability-advisories-cve-2026-26101.