What is CVE-2026-20945?
Improper neutralization of input during web page generation ('cross-site scripting') in Microsoft Office SharePoint allows an authorized attacker to perform spoofing over a network.
The record classifies CVE-2026-20945 under weakness class CWE-79. Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs low-privilege credentials, needs a user to take an action first. 3 affected-product entries are recorded, across 1 vendor, listed below. The identifier was first published 197 days ago.
Severity and exploitation probability
- CVSS v3.1 base score
- 4.6 — MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N - EPSS (FIRST)
- 19.0% probability of exploitation in the next 30 days, higher than 97.2% of all scored CVEs
- CISA KEV
- Not listed in the CISA Known Exploited Vulnerabilities catalog
- Threadlinqs priority
- 6.2/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- Published
- 2026-04-14, last modified 2026-09-25
Is CVE-2026-20945 being exploited?
It currently carries a trending score of 29 in the Threadlinqs vulnerability feed.
Affected products and versions
- Microsoft: SharePoint Enterprise Server 2016, SharePoint Server 2019, SharePoint Server Subscription Edition
How to fix CVE-2026-20945
The record marks a vendor fix as available for CVE-2026-20945. Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20945. Apply the vendor fix referenced above to every affected product listed in this record, then confirm the running version against the vendor advisory.
Threat activity tracking CVE-2026-20945
1 tracked threat in the Threadlinqs corpus references CVE-2026-20945, either in the campaign’s CVE list or as an indicator on the campaign record.
Sources
Enriched from CVE.org, FIRST EPSS, GitHub Security Advisories. Last verified by Threadlinqs on .