Raw vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:N/VA:N/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:XSummary
CVE-2026-20999 is a high-severity Authentication Bypass by Capture-replay (CWE-294) vulnerability in Samsung Smart Switch. Its CVSS base score is 7.1 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Network Sniffing (T1040); ranked at the 24th 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 SC-23 (Session Authenticity) and SC-8 (Transmission Confidentiality and Integrity) — 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-2026-20999 is an authentication bypass vulnerability caused by a replay attack in Samsung Smart Switch versions prior to 3.7.69.15. This flaw, associated with CWE-294, enables remote attackers to circumvent authentication mechanisms and execute privileged functions without valid credentials. The vulnerability received a CVSS v3.1 base score of 7.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N), highlighting its high severity due to network accessibility, low attack complexity, and significant integrity impact.
Remote attackers can exploit this vulnerability over the network without requiring user interaction or prior privileges. By capturing and replaying authentication-related data, they can trigger privileged operations within Smart Switch, potentially leading to unauthorized control over device management functions, data transfers, or other high-privilege actions supported by the software.
The Samsung security advisory at https://security.samsungmobile.com/serviceWeb.smsb?year=2026&month=03 provides details on the issue, including recommendations to update to Smart Switch version 3.7.69.15 or later to mitigate the replay-based authentication bypass.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-12315
Vulnerability Data
Authentication bypass by replay in Smart Switch prior to version 3.7.69.15 allows remote attackers to trigger privileged functions.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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V10.4.16V10.5.1
Mitigating Controls (NIST 800-53 r5) AI
Session authenticity mechanisms directly stop replay of captured authentication traffic by enforcing freshness or cryptographic binding.
Transmission integrity (with anti-replay) stops captured messages from being accepted as valid later.
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.
Protecting and verifying identity assertions prevents replay of captured authentication material.
Encryption and integrity protections for data-in-transit directly block capture-replay of credentials or tokens.
Network monitoring may detect anomalous replays after the fact but does not prevent the design flaw.
Strong authentication methods can reduce replay risk but do not inherently address captured messages.
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.
Cryptographic protections (e.g., nonces, timestamps, message authentication codes) make captured authentication messages unusable for replay.
Secure authentication mechanisms directly prevent replay attacks by requiring fresh, non-replayable credentials or tokens.
Network security controls such as encryption and integrity protection reduce the feasibility of capturing and replaying authentication traffic.
Application security requirements can mandate replay-resistant authentication designs, but the control itself does not prescribe the technical measures.