Raw vector
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:HSummary
CVE-2026-28313 is a critical-severity Authorization Bypass Through User-Controlled Key (CWE-639) vulnerability in Solarwinds Serv-U. Its CVSS base score is 9.1 (Critical).
Operationally, exploitation aligns with the MITRE ATT&CK technique Account Manipulation (T1098); ranked at the 27th 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-24 (Access Control Decisions) — see the control section below for these in your framework.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-46293
Vulnerability Data
SolarWinds Serv-U is affected by an insecure direct object reference (IDOR) vulnerability that can lead to SMTP hijacking leading to arbitrary account takeover. The impact is lower in Windows deployments.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
IDOR directly enables SMTP config manipulation for arbitrary account takeover (T1098 Account Manipulation).
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
Mitigating Controls (NIST 800-53 r5) AI
Directly enforces authorization checks on object references, blocking the IDOR that enables SMTP config hijacking and account takeover.
Restricts privileges on SMTP and account objects so that even a successful IDOR yields minimal unauthorized access.
Requires explicit, policy-driven access decisions for every object reference, mitigating the authorization bypass in CWE-639.
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.
Enforcing authorization policy and least privilege directly blocks user-controlled key tampering that bypasses access checks.
Logical access controls prevent unauthorized data access that results from missing authorization checks on object references.
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 can detect missing authorization checks but does not prevent the weakness in production.
Information access restriction explicitly enforces that users may only retrieve data they are authorized to see, directly addressing user-controlled key bypass.
Access control policy directly requires enforcement of authorization rules that prevent unauthorized access via manipulated keys.
Managing access rights includes ensuring users can only access their own records and not bypass authorization by altering identifiers.
Privileged access rights control restricts what data each user may access, mitigating direct object reference attacks.
Secure development lifecycle includes authorization design but does not itself implement runtime access checks.