Raw vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:NSummary
CVE-2026-20151 is a high-severity Insertion of Sensitive Information Into Sent Data (CWE-201) vulnerability in Cisco Smart Software Manager On-Prem. Its CVSS base score is 7.3 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Network Sniffing (T1040); ranked at the 19th 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-4 (Information Flow Enforcement) — 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-2026-20151 is a privilege escalation vulnerability in the web interface of Cisco Smart Software Manager On-Prem (SSM On-Prem). It stems from improper transmission of sensitive user information, enabling an authenticated, remote attacker to retrieve session credentials. The issue affects systems where users log in via the web interface, but does not impact SSH sessions or expose information about non-active web sessions.
An attacker with valid credentials for a user account holding at least the System User role can exploit this by sending a crafted message to the SSM On-Prem host and capturing session credentials from subsequent status messages. Exploitation requires user interaction (UI:R) and has a CVSS v3.1 base score of 7.3 (AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N), allowing elevation from low privileges to administrative access on the affected system, with high confidentiality and integrity impacts but no availability effects. The root cause is classified under CWE-201 (Exposure of Sensitive Information to an Unauthorized Actor).
The official Cisco Security Advisory provides details on this vulnerability, including affected versions and recommended mitigations, available at https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-cssm-priv-esc-xRAnOuO8. Security practitioners should consult it for patching instructions and workarounds.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-17954
Vulnerability Data
A vulnerability in the web interface of Cisco Smart Software Manager On-Prem (SSM On-Prem) could allow an authenticated, remote attacker to elevate privileges on an affected system. This vulnerability is due to the improper transmission of sensitive user information. An…
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attacker could exploit this vulnerability by sending a crafted message to an affected Cisco SSM On-Prem host and retrieving session credentials from subsequent status messages. A successful exploit could allow the attacker to elevate privileges on the affected system from low to administrative. To exploit this vulnerability, the attacker must have valid credentials for a user account with at least the role of System User. Note: This vulnerability exposes information only about users who logged in to the Cisco SSM On-Prem host using the web interface and who are currently logged in. SSH sessions are not affected.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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- 1 hardening rule · 1 OS baseline
V14.2.3
Mitigating Controls (NIST 800-53 r5) AI
Directly enforces policy-based information flow rules that block transmission of sensitive data to unauthorized actors.
Enforces authorizations on logical access so that sensitive data is not released to unauthorized recipients.
Requires validation of outbound information to ensure sensitive content is not disclosed in responses or messages.
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 prevent insertion of sensitive data into application outputs and messages.
Monitoring runtime data flows and outputs can detect sensitive data being transmitted.
Protecting data-in-transit can include filtering or encrypting to avoid exposing sensitive content.
Protecting data-in-use includes removing confidential values before they are processed or sent.
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.
Data-masking techniques can prevent sensitive values from appearing in transmitted payloads.
Classification identifies sensitive data so it is not inadvertently transmitted.
Labelling makes sensitive data visible to developers and prevents accidental inclusion in outbound messages.
Information-transfer rules directly govern what data may be sent to external parties.
PII-protection requirements reduce the chance of sending personal data to unauthorized recipients.
DLP controls inspect and block outbound flows that contain sensitive information.