Security readout for executives and security teams
Plain-English summary
CVE-2020-17126 is a Microsoft Excel information disclosure vulnerability. It could allow a local, low-privileged user to obtain sensitive information. Public data rates it medium severity, with high confidentiality impact but no integrity or availability impact. No source provided indicates active exploitation.
Executive priority
Treat as a routine but important patching item. The main business risk is unauthorized disclosure of sensitive data on systems where an attacker already has local access. Prioritize shared endpoints, high-value workstations, and Office server components.
Technical view
The CVSS 3.1 vector is AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N, score 5.5. Affected products include Microsoft Excel 2010/2013/2016, Office 2019, Office 2019 for Mac, Microsoft 365 Apps for Enterprise, Office Online Server, and Office Web Apps 2013 SP1. Microsoft lists an official advisory and patch reference.
Likely exposure
Exposure is most likely where affected Microsoft Excel or Office components remain unpatched, including desktop, Mac, and server-based Office deployments listed by Microsoft. Because attack vector is local, risk is higher on shared systems, virtual desktops, and endpoints where untrusted users have accounts.
Exploitation context
The provided sources do not show CISA KEV listing or confirmed active exploitation. CVSS exploit code maturity is listed as unproven. The weakness requires local access and low privileges, with no user interaction indicated by the CVSS vector.
Researcher notes
The public bundle does not include root-cause detail, CWE classification, or exploit mechanics. Avoid assuming remote document-based exploitation from the available CVSS vector. Use the Microsoft advisory as the authoritative source for affected product mapping and remediation status.
Mitigation direction
- Apply the Microsoft security update referenced in the MSRC advisory.
- Prioritize systems running affected Office, Excel, Office Online Server, or Office Web Apps versions.
- Retire or isolate unsupported legacy Office installations where updates cannot be applied.
- Check Microsoft guidance for any product-specific update prerequisites or deployment notes.
Validation and detection
- Inventory Office and Excel versions across endpoints and servers.
- Compare installed versions against the Microsoft advisory for CVE-2020-17126.
- Confirm security updates were successfully installed on affected assets.
- Review patch management reports for failed or deferred Office updates.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CVE-2020-17126 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 5.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C1.83.6microsoftVulnerability scoring details
Base CVSS 3.1 score
5.5MediumVector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- Microsoft Excel Information Disclosure VulnerabilityCVE reference, microsoft · vendor-advisory, patch
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2020-17126CVE reference, CVE · x_refsource_MISC, x_transferred
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.