Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HSummary
CVE-2026-20846 is a high-severity Buffer Over-read (CWE-126) vulnerability in Microsoft Windows 10 21H2. Its CVSS base score is 7.5 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique OS Credential Dumping (T1003); ranked in the top 31% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SA-8 (Security and Privacy Engineering Principles) — 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-2026-20846 is a buffer over-read vulnerability (CWE-126) in the Windows GDI+ graphics component. Published on 2026-02-10, it carries a CVSS v3.1 base score of 7.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H), indicating high severity primarily due to its potential for availability disruption.
An unauthorized attacker can exploit this vulnerability remotely over a network with low attack complexity, requiring no user privileges or interaction. Successful exploitation results in a denial-of-service condition with high impact on availability, but no impact on confidentiality or integrity.
The Microsoft Security Response Center has published an update guide detailing mitigations for CVE-2026-20846 at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20846.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-7309
Vulnerability Data
Buffer over-read in Windows GDI+ allows an unauthorized attacker to deny service over a network.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Developer testing and evaluation (static analysis, fuzzing, bounds checking tests) directly finds buffer over-read flaws.
Engineering principles such as memory-safe design and bounds-checked abstractions structurally stop introduction of out-of-bounds reads.
Process isolation limits the blast radius of an over-read to the compromised domain.
Input validation enforces length and index constraints that prevent many externally triggered over-reads.
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 development practices directly prevent introduction of buffer over-read weaknesses.
Vulnerability identification processes can discover buffer over-read flaws via scanning or review.
Patching or replacing vulnerable software removes known instances of buffer over-read bugs.
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 buffer over-reads before release.
Secure SDLC mandates input validation and bounds checking that can prevent buffer over-reads.
Application security requirements can specify buffer-size and bounds-checking rules.
Secure architecture principles include memory-safety and bounds-checking design choices.
Secure coding standards directly require bounds-checked buffer access, mitigating over-reads.