CVE-2026-45498: Microsoft Defender Denial of Service Vulnerability
Advisory generated from the CVE record, CISA, Exploit Observer and VEDAS: what it is, whether it is exploited, who is affected, and how to fix and detect it.
Generated by VEDAS. Scores as of 2026-11-01 19:19 UTC. Rebuilt every few hours from cve-scores, CISA KEV and vedas-signatures. How this works and its limits.
What it is
Microsoft Defender Denial of Service Vulnerability
Description quoted from the CVE record (assigned by microsoft, published 2026-05-20).
Weakness: CWE-400: Uncontrolled Resource Consumption
How it can be exploited
Exploitable with local access with low attack complexity needing no privileges and no user interaction. Impact: confidentiality none, integrity none, availability low. CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L/E:U/RL:O/RC:C
CISA assessment (SSVC): CISA assesses exploitation as active. Automatable: no. Technical impact: partial.
- On CISA KEV since
- 2026-05-20
- US federal deadline
- 2026-06-03
- Ransomware use
- Not known
Public exploit evidence (Exploit Observer)
Also known as: BDU:2026-07109, EUVD-2026-31102, GHSA-8gp3-pghr-6wxp
Exploit Observer has no public exploit code that names this CVE or one of its aliases.
Research and write-ups (1)
- Research or write-up: https://thecyberexpress.com/cve-2026-41091-cve-2026-45498-cvss-exploit
Vulnerability databases and vendor advisories (5)
Catalogue entries, not exploit evidence.
- Vulnerability database or vendor advisory: https://euvd.enisa.europa.eu/enisa/EUVD-2026-31102
- Vulnerability database or vendor advisory: https://github.com/advisories/GHSA-8gp3-pghr-6wxp
- Vulnerability database or vendor advisory: https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2026-45498
- Vulnerability database or vendor advisory: https://nvd.nist.gov/vuln/detail/CVE-2026-45498
- Vulnerability database or vendor advisory: https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-45498
3 more references returned by Exploit Observer did not name this CVE or an alias, so they are left out.
VEDAS data as of 2026-11-01T17:12 UTC; fetched 2026-11-02.
Live scores
- EPSS
- 0.631
very likely to be attacked soon - VEDAS
- 0.659
some exploit evidence - On CISA KEV
- Yes, since 2026-05-20
- Detection rule
- None yet
Thin horizontal line: the “likely” (EPSS 0.10) or “strong” (VEDAS 0.90) threshold. Shaded “no data” areas are periods when cve-scores did not publish.
Who is affected
| Product | Affected | Not affected |
|---|---|---|
| Microsoft Microsoft Defender Antimalware Platform | from 4.0.0.0 before 4.18.26040.7 | Not stated |
Version ranges exactly as the CVE record states them. “Before X” means X is the first fixed version.
Exploit Observer also maps it to: microsoft defender_antimalware_platform, microsoft_corp microsoft_defender_antimalware_platform.
How to fix it
Fixed versions stated in the CVE record: 4.18.26040.7.
CISA required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Vendor guidance:
- Microsoft Defender Denial of Service Vulnerability (vendor-advisory, patch)
How to detect it
There is no open VEDAS detection rule for this bug yet. It is listed on the detection gaps page if CISA has confirmed attacks.
Advisories on this CVE
References
Vendor advisories and patches
- Microsoft Defender Denial of Service Vulnerability (vendor-advisory, patch)
Government sources
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-45498 (government-resource)
Other databases
Where this comes from
This advisory is generated automatically by VEDAS from: CVE.org record, CISA KEV, cve-scores (EPSS and VEDAS), Exploit Observer. Text in quotes is reproduced from the source; everything else is a fixed template filled with source fields. Nothing here is written by a language model. Check the vendor advisory before acting, and read how VEDAS and Exploit Observer work, and their limits.