Security Resilience

CVE-2026-20081

Path Traversal

Published
15 April 2026
Modified
17 April 2026
CVSS Score v3.1 6.5
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
EPSS Score 0.0039 32th percentile
Risk Priority 50 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-2026-20081 is a medium-severity Relative Path Traversal (CWE-23) vulnerability in Cisco Unity Connection (inferred from references). Its CVSS base score is 6.5 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 32th 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 SI-10 (Information Input Validation) and AC-3 (Access Enforcement) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

Multiple vulnerabilities in Cisco Unity Connection could allow an authenticated, remote attacker to download arbitrary files from an affected system. To exploit these vulnerabilities, the attacker must have valid administrative credentials.  These vulnerabilities are due to improper sanitization of user input…

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to the web-based management interface. An attacker could exploit these vulnerabilities by sending a crafted HTTPS request. A successful exploit could allow the attacker to download arbitrary files from an affected system.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

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.
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
T1687 Exploitation for Defense Impairment Defense Impairment
Adversaries may exploit vulnerabilities in security software, infrastructure, or defensive components to degrade, disable, or otherwise continue to impair their ability to prevent, detect, or respond to malicious activity.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-84939Shared CWE-23
CVE-2026-31831Shared CWE-23
CVE-2026-50016Shared CWE-23
CVE-2026-20078Shared CWE-23
CVE-2025-66737Shared CWE-23
CVE-2025-58456Shared CWE-23
CVE-2025-32137Shared CWE-23
CVE-2025-58463Shared CWE-23
CVE-2026-83873Shared CWE-23
CVE-2026-5422Shared CWE-23

Affected Assets

Cisco
Unity Connection
inferred from references and description; NVD did not file a CPE for this CVE

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)
  • V5.3.2

Mitigating Controls (NIST 800-53 r5) AI

Explicit validation of path inputs stops .. sequences from ever being interpreted by the file system.

Access enforcement directly blocks unauthorized file reads/writes that result from unresolved .. sequences.

Information-flow rules can be configured to reject traversals that would move data outside an approved directory boundary.

Least privilege reduces the set of reachable files even when a traversal succeeds.

Secure-engineering principles require safe pathname construction and input neutralization before any file operation.

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-06 mostly match
blocks

Secure SDLC practices directly require input validation and path sanitization that prevent relative traversal.

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.

finds

Security testing in development catches path traversal via static/dynamic analysis, but does not itself implement the fix.

prevents

Secure coding standards require neutralizing path traversal sequences, directly addressing CWE-23.

References