XSS in Microsoft Live Share Canvas

CVE-2026-45644

Improper neutralization of input during web page generation ('cross-site scripting') in Microsoft Live Share Canvas SDK allows an authorized attacker to elevate privileges over a network.

Vulnerability class: XSS (Cross-Site Scripting)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 8.0 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.008 (55.5th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 55th percentile — 55.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-45644: held from 0.006 to 0.008.

EPSS over last 30 days · oldest: 0.006 · newest: 0.008 · change: +0.003

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-45644?
CVE-2026-45644 is a high-severity vulnerability in Microsoft Live Share Canvas, classified under Cross-site Scripting. CVSS score: 8.0/10. Published 2026-06-09.
How severe is CVE-2026-45644?
High severity. CVSS v3 base score is 8.0 out of 10.