Raw vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:P/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-2026-2148 is a medium-severity Exposure of Sensitive Information to an Unauthorized Actor (CWE-200) vulnerability in Tenda Ac21 Firmware. Its CVSS base score is 5.5 (Medium).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 42th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified map to AC-3 (Access Enforcement) and IA-2 (Identification and Authentication (Organizational Users)) — 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-2026-2148 is an information disclosure vulnerability affecting the Tenda AC21 router on firmware version 16.03.08.16. The issue resides in an unknown function of the /cgi-bin/DownloadFlash file within the Web Management Interface component. Published on 2026-02-08, it has a CVSS v3.1 base score of 5.3 (AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N) and is linked to CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor) and CWE-284 (Improper Access Control).
The vulnerability enables remote exploitation without authentication, privileges, or user interaction, requiring only low attack complexity over the network. Attackers can manipulate the affected function to disclose sensitive information, though the impact is limited to low confidentiality loss with no effects on integrity or availability.
Advisories and further details are documented in VulDB entries (ctiid.344850, id.344850, submit.747557), a GitHub issue at master-abc/cve/issues/27, and on the Tenda website at tenda.com.cn.
The exploit has been publicly disclosed and may be used by attackers.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-5801
Vulnerability Data
A security vulnerability has been detected in Tenda AC21 16.03.08.16. Affected is an unknown function of the file /cgi-bin/DownloadFlash of the component Web Management Interface. The manipulation leads to information disclosure. It is possible to initiate the attack remotely. The…
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exploit has been disclosed publicly and may be used.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Direct unauthenticated remote exploitation of the web management interface (/cgi-bin/DownloadFlash) on a publicly exposed router matches T1190 Exploit Public-Facing Application; info disclosure enables initial access and reconnaissance but no other Enterprise techniques are directly facilitated.
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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- 15 hardening rules · 10 OS baselines
V10.4.9V11.7.1V14.1.2V14.2.4
Mitigating Controls (NIST 800-53 r5) AI
Directly enforces authorization checks on the /cgi-bin/DownloadFlash endpoint to block unauthenticated remote access that triggers the disclosure.
Requires identification and authentication before any access to the Web Management Interface, eliminating the no-authentication attack vector.
Restricts and authorizes remote management connections to the router, limiting exposure of the vulnerable CGI function.
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 directly enforces least-privilege authorization that blocks most unauthorized disclosures, yet CWE-200 also arises from logging, error messages, and side-channel paths that access controls alone do not address.
PR.DS-10 mostly prevents CWE-200 by directly eliminating unauthorized access to sensitive data-in-use, yet only partially addresses the weakness because CWE-200 spans many other exposure vectors outside runtime protection.
PR.IR-01's segmentation/zero-trust controls largely eliminate network-level unauthorized access paths that enable exposure, yet CWE-200 spans many additional vectors (API responses, logs, app logic) that network controls alone cannot close.
Hardened baselines and deviation monitoring directly eliminate most configuration-induced access-control defects, yet CWE-284 also encompasses code-level and design flaws outside the scope of configuration management alone.
Secure SDLC practices catch most exposure flaws via design, testing and release controls, yet CWE-200 spans runtime/config issues a single development outcome cannot fully close.
PR.AA-01 supplies proper credential lifecycle controls that reduce unauthorized access paths, yet leaves many other exposure vectors (error messages, logging, side channels, etc.) unaddressed.
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.
Defining and enforcing explicit access rights and restrictions for each entity directly stops the assignment of permissions that exceed what is required, eliminating the root condition that allows improper access control.
Formal authorization, role-based provisioning, and timely revocation of access rights directly stop the creation of accounts or permissions that exceed what the business actually needs.
Restricting anonymous or unknown access and encrypting high-value information limits the exposure of sensitive data that would otherwise be obtainable by unauthorized actors.
Suppressing system details, error specifics, and previous log-on information until successful authentication reduces the information an unauthenticated attacker can gather.
By requiring owners to assign sensitivity labels and corresponding handling rules, the control ensures that information is not left unmarked and therefore reduces the chance that sensitive data will be exposed to unauthorized actors.
Requiring encryption, access controls, and recipient authentication for transfers directly reduces the chance that sensitive data reaches an unauthorized observer.