Cyber Resilience

CVE-2026-26101

LPE in Owlcyberdefense Opds-Talon 2.2.0.4

Published
20 February 2026
Modified
27 February 2026
CVSS Score v4 8.5
Click a component to see what it means
Raw vectorCVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/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 0.0011 1th percentile
Risk Priority 30 floored blend · peak EPSS

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 8.5 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Credentials In Files (T1552.001); ranked at the 1th 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.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

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.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

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

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1552.001 Credentials In Files Credential Access
Adversaries may search local file systems and remote file shares for files containing insecurely stored credentials.
T1552.004 Private Keys Credential Access
Adversaries may search for private key certificate files on compromised systems for insecurely stored credentials.
T1574.005 Executable Installer File Permissions Weakness Stealth
Adversaries may execute their own malicious payloads by hijacking the binaries used by an installer.
T1574.010 Services File Permissions Weakness Stealth
Adversaries may execute their own malicious payloads by hijacking the binaries used by services.
T1505.005 Terminal Services DLL Persistence
Adversaries may abuse components of Terminal Services to enable persistent access to systems.
T1548 Abuse Elevation Control Mechanism Privilege Escalation
Adversaries may circumvent mechanisms designed to control privilege elevation to gain higher-level permissions.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-26102Same product: Owlcyberdefense Opds-100
CVE-2026-26096Same product: Owlcyberdefense Opds-100
CVE-2026-26095Same product: Owlcyberdefense Opds-100
CVE-2026-26093Same product: Owlcyberdefense Opds-100
CVE-2026-26097Same product: Owlcyberdefense Opds-100
CVE-2026-26098Same product: Owlcyberdefense Opds-100
CVE-2026-2333Same product: Owlcyberdefense Opds-100
CVE-2026-26099Same product: Owlcyberdefense Opds-100
CVE-2026-1344Shared CWE-732
CVE-2026-16157Shared CWE-732

Affected Assets

owlcyberdefense
opds-talon
2.2.0.4

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 7 hardening rules · 4 OS baselines
Validate
Prove the fix (OWASP ASVS)

Mitigating Controls (NIST 800-53 r5) AI

Enforces the access control policy that defines permissions on resources, thereby stopping incorrect assignments from remaining exploitable.

Directly requires assignment of only the minimum necessary permissions, preventing overly broad grants on critical resources.

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.AA-05 full match
prevents

Directly requires defining, enforcing, and reviewing access permissions and least privilege on resources.

PR.PS-01 mostly match
prevents

Hardened baselines and configuration management explicitly include correct permission settings for critical resources.

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.

prevents

By requiring owners to determine and document the exact permissions needed for each asset, the control reduces the likelihood that default or overly permissive file and resource permissions will be left in place.

prevents

Documented provisioning and revocation procedures reduce the chance that critical resources retain overly permissive default or leftover permissions after personnel changes.

prevents

Documented authorization, expiry rules, and audit logging of privileged accounts make it harder for critical resources to retain overly permissive or stale permission assignments.

prevents

Requiring explicit configuration of access controls and permissions for files, applications and services counters the assignment of overly permissive default or incorrect file-system rights.

prevents

Enforcing differentiated permissions on the source-code repository and program listings stops the assignment of overly broad default or inherited permissions to critical resources.

prevents

By defining and enforcing secure permission settings in configuration templates, the control reduces the likelihood that critical resources receive incorrect permission assignments.

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).

Oracle Linux 8 (1 rule)
  • V-248577 OL 8 must enable kernel parameters to enforce Discretionary Access Control (DAC) on symlinks. prevents CWE-732
Windows Server 2016 (2 rules)
  • V-224972 Active Directory Group Policy objects must have proper access control permissions. prevents CWE-732
  • V-224831 Local volumes must use a format that supports NTFS attributes. prevents CWE-732
Windows Server 2019 (2 rules)
  • V-205741 Windows Server 2019 Active Directory Group Policy objects must have proper access control permissions. prevents CWE-732
  • V-205663 Windows Server 2019 local volumes must use a format that supports NTFS attributes. prevents CWE-732
Windows Server 2022 (2 rules)
  • V-254393 Windows Server 2022 Active Directory Group Policy objects must have proper access control permissions. prevents CWE-732
  • V-254250 Windows Server 2022 local volumes must use a format that supports NTFS attributes. prevents CWE-732

References