CVE-2020-0638
An elevation of privilege vulnerability exists in the way the Update Notification Manager handles files.To exploit this vulnerability, an attacker would first have to gain execution on the victim system, aka 'Update Notification Manager Elevation of Privilege Vulnerability'.
- CVSS
- 7.8Highscored by CISA
- Exploited in the wild
- Yes, in CISA KEV since 23 May 2022CISA deadline for US federal agencies: 13 Jun 2022known use in ransomware campaigns
- EPSS
- 2.5%chance of exploitation in the next 30 daystop 15% of scored CVEsFIRST score of 11 Nov 2026
- Fix
- Patch availablesee the advisories in the references
- Published
- 14 Jan 2020analysed here 12 Nov 2026
Do first. Apply updates per vendor instructions. (CISA's required action for this KEV entry)
Summary
Triage
The summary, impact and action text on this page are written by our AI analysis pipeline, or taken from the NVD description when a CVE was imported from NVD. They are not the vendor's wording: check them against the sources. A longer AI executive summary and technical analysis are generated for signed-in accounts on the Max plan.
Affected products
| Product | Affected versions | Vendor says fixed in |
|---|---|---|
| Microsoft Windows | 10 Version 1709 for 32-bit Systems10 Version 1803 for 32-bit Systems10 Version 1809 for ARM64-based Systems10 Version 1803 for x64-based Systems10 Version 1709 for ARM64-based Systems10 Version 1709 for x64-based Systems10 Version 1803 for ARM64-based Systems10 Version 1809 for 32-bit Systems10 Version 1809 for x64-based SystemsVendor says fixed in: not stated | |
| Microsoft Windows Server | 20192019 (Core installation)version 1803 (Core Installation)Vendor says fixed in: not stated |
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.
Products named in our analysis
- microsoft:windows_10_1709
- microsoft:windows_10_1803
- microsoft:windows_10_1809
- microsoft:windows_10_1903
- microsoft:windows_10_1909
- microsoft:windows_server_1803
- microsoft:windows_server_1903
- microsoft:windows_server_1909
- microsoft:windows_server_2019
Fix and mitigation
WAF and other mitigations
Can a WAF block it? No. The attack needs local access to the machine, so a WAF is not on its path.
Also consider: patch
Based on the attack vector (local or physical access). We check Cloudflare, AWS, Google Cloud Armor and Azure; for Akamai, Imperva, Fastly, F5, ask your vendor.
Remediation steps (AI-written)
Step-by-step remediation is generated for accounts on the Max plan, for CVEs that match a technology in their stack. Add this technology to your stack to see the fix checklist.
Exploitation evidence
- CISA KEV catalog
- Listed since 23 May 2022. Known use in ransomware campaigns.
- CISA due date
- 13 Jun 2022, the remediation deadline for US federal agencies
- CISA required action
- Apply updates per vendor instructions.
- Public exploit code
- None on record in Exploit-DB, Metasploit, Nuclei templates or PoC-in-GitHub.
- CISA SSVC
- exploitation active, automatable no, technical impact totalAssessed by CISA 1 Jul 2022 (SSVC 2.0.3). Exploitation is none, poc (public proof of concept) or active.
Timeline
- 14 Jan 2020Published
- 23 May 2022Added to CISA KEV (exploited in the wild)859 days (about 2 years) later
- 13 Jun 2022CISA remediation due date (US federal agencies)21 days later
- 1 Jul 2022CISA SSVC assessment: exploitation active18 days later
- 12 Aug 2026CVE record last updated1,503 days (about 4 years) later
- 12 Nov 2026Analysed by vulneraibility.com92 days (about 3 months) later
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
| Metric | Value | What it means |
|---|---|---|
| Attack vector | LocalLocal access required (shell, logged-in user). | Local access required (shell, logged-in user). |
| Attack complexity | LowRepeatable attack, no special conditions. | Repeatable attack, no special conditions. |
| Privileges required | LowThe attacker needs basic user privileges. | The attacker needs basic user privileges. |
| User interaction | NoneNo victim action needed. | No victim action needed. |
| Scope | UnchangedImpact stays within the vulnerable component. | Impact stays within the vulnerable component. |
| Confidentiality | HighTotal data disclosure possible. | Total data disclosure possible. |
| Integrity | HighComplete modification possible. | Complete modification possible. |
| Availability | HighFull outage possible. | Full outage possible. |
Common questions
Is CVE-2020-0638 being exploited?
Yes. CVE-2020-0638 appears in CISA's Known Exploited Vulnerabilities catalog, which means exploitation in the wild has been confirmed and reported. Treat it as active rather than theoretical, and patch it ahead of higher-scoring vulnerabilities that carry no exploitation evidence.
How severe is CVE-2020-0638?
CVE-2020-0638 is rated High with a CVSS score of 7.8. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2020-0638?
Yes. A fix has been recorded for CVE-2020-0638. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2020-0638 affect?
CVE-2020-0638 affects microsoft:windows_10_1709, microsoft:windows_10_1803, microsoft:windows_10_1809, microsoft:windows_10_1903, and 5 further products or versions. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
References
2 references in the CVE record, grouped by the tags the record gives them.
Other links (2)
- portal.msrc.microsoft.com /en-US/security-guidance/advisory/CVE-2020-0638
- cisa.gov /known-exploited-vulnerabilities-catalog?field_cve=CVE-2020-0638
Where the data on this page comes from
- CVE List (CVE.org): description, affected versions, references; CVE Terms of Use
- NVD: CVSS and CPE data
- CISA KEV catalog: exploitation, date added, due date
- CISA Vulnrichment (ADP): SSVC decision points
- FIRST EPSS: exploit probability and percentile
Summary, impact and triage tags: written by our AI analysis pipeline from the sources above. Check them against the sources.
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