Security readout for executives and security teams
Plain-English summary
This SharePoint flaw lets a signed-in attacker inject browser-displayed content that may impersonate trusted information or mislead another user. Exploitation requires network access, valid privileges, and victim interaction. The supplied severity is medium, with limited confidentiality and integrity impact and no availability impact.
Executive priority
Schedule remediation through the normal security-update cycle, with faster treatment for broadly accessible or multi-user SharePoint environments. This is not supported as an emergency-level threat by the supplied evidence, but spoofing and script execution within a trusted collaboration platform can enable convincing user deception.
Technical view
CVE-2026-45479 is a CWE-79 cross-site scripting vulnerability caused by improper input neutralization during page generation. It affects listed SharePoint Server 2016, 2019, and Subscription Edition products. CVSS 3.1 is 4.6: network-accessible, low complexity, low privileges required, user interaction required, unchanged scope, and low confidentiality and integrity impact.
Likely exposure
Organizations operating the listed on-premises SharePoint products may be exposed where authorized users can reach affected functionality over a network. Risk is higher when potentially untrusted users hold SharePoint accounts or can influence content viewed by other users. The supplied evidence does not identify exact vulnerable builds beyond version 16.0.0.
Exploitation context
The attacker must already be authorized, and successful exploitation requires another user to interact with maliciously generated content. The supplied bundle marks this CVE as absent from KEV and provides no evidence of active exploitation. No exploit maturity beyond the CVSS temporal metric E:U is established.
Researcher notes
The supplied record establishes CWE-79 and CVSS 4.6, but does not describe the vulnerable input path, execution context, affected build ranges, update identifiers, or detection indicators. Researchers should rely on Microsoft’s advisory for build-specific applicability. Avoid treating the generic 16.0.0 entries as complete patch-level boundaries without vendor confirmation.
Mitigation direction
- Review Microsoft’s CVE advisory for the applicable SharePoint security update.
- Apply Microsoft’s update to affected SharePoint deployments using normal change controls.
- Restrict SharePoint access and privileges while remediation is pending.
- Prioritize environments where less-trusted users can create content viewed by others.
Validation and detection
- Inventory SharePoint Server 2016, 2019, and Subscription Edition deployments.
- Compare installed builds against Microsoft’s current CVE advisory.
- Confirm the applicable Microsoft security update is installed on every server.
- Verify update completion across all nodes in each SharePoint farm.
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.
CWE-79: User-session and phishing behavior lookup
Client-side and session-facing weaknesses should be reviewed alongside initial-access and user-execution behaviors. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2026-45479 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
- 4.6 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/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.
SSVC decision data
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:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N/E:U/RL:O/RC:C2.12.5microsoftVulnerability scoring details
Base CVSS 3.1 score
4.6MediumVector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/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 SharePoint Server Spoofing VulnerabilityCVE reference, microsoft · vendor-advisory, patch
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.
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.