5.5

CVE-2026-63529: microsoft 365_apps Out-of-bounds Read

CVSS: 5.5v3.1MediumAnalyzed
Published 11-08-2026Last modified 08-10-2026

Vulnerability summary

CVE-2026-63529 is a medium (CVSS 5.5) Out-of-bounds Read vulnerability in microsoft 365_apps. EPSS estimates a 0.54% chance of exploitation in the next 30 days, higher than 44.3% of scored vulnerabilities.

Overall risk
22/100
0100
Low · default modelHow is this calculated?
CVSS score
5.5/10
010
Medium · v3.1 (CVE.org)
EPSS score
0.54%
0%100%
Low · +0.20 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 11-08-2026
    PublishedVulnerability first disclosed.
  2. 08-10-2026
    Last modifiedVulnerability information updated.

Description

Out-of-bounds read in Microsoft Office allows an unauthorized attacker to disclose information locally.

CVSS metrics

2 scores · 2 sources · 1 version

EPSS trend

Probability

0.54%

Chance of exploitation in the next 30 days

Percentile

44%

Versus all other CVEs

30-day change

+0.20 pp

From 0.34% on 19-09-2026

19-09-202619-10-2026
EPSS score
0.54%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Microsoft10 products

1 vendor · 10 products

References

1 links