CVE-2026-20034
Cisco Unity Connection ≤ 14.0
Raw vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HSummary
CVE-2026-20034 is a high-severity Path Traversal: '.../...//' (CWE-35) vulnerability in Cisco Unity Connection. Its CVSS base score is 8.8 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Data from Local System (T1005); ranked in the top 50% of CVEs by exploit likelihood; 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.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-27847
Vulnerability Data
A vulnerability in the web-based management interface of Cisco Unity Connection could allow an authenticated, remote attacker to execute arbitrary code on an affected device. This vulnerability is due to insufficient validation of user-supplied input. An attacker could exploit this…
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vulnerability by submitting a crafted API request. A successful exploit could allow the attacker to execute arbitrary code as root, possibly resulting in the complete compromise of a targeted device. To exploit this vulnerability, the attacker must have valid user credentials on the affected device.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Input validation directly neutralizes path sequences so the traversal cannot be introduced or exploited.
Enforces access authorizations on the resulting pathname, blocking traversal attempts from succeeding.
Enforces information flow rules that stop unauthorized directory escapes via crafted paths.
Least privilege reduces the impact of any successful traversal by limiting accessible 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.
Secure SDLC practices directly require input validation and path sanitization that neutralize traversal sequences.
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.
Security testing in development can detect path-traversal flaws before release.
Secure SDLC mandates input validation and path-handling controls that directly mitigate path traversal.
Application security requirements include rules for safe file-path construction and canonicalization.
Secure architecture principles require proper directory restrictions and input sanitization to prevent traversal.
Secure coding standards explicitly forbid unsafe path concatenation and mandate canonicalization routines.
Information access restriction limits file reachability but does not address the input-validation flaw itself.