CVE-2026-63531: microsoft 365_apps Out-of-bounds Read
CVSS: 5.5v3.1MediumAnalyzed
Published 11-08-2026Last modified 08-10-2026
Vulnerability summary
CVE-2026-63531 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.
CVSS score
5.5/10
010
Medium · v3.1 (CVE.org)EPSS score
0.54%
0%100%
Low · +0.20 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Timeline
- 11-08-2026PublishedVulnerability first disclosed.
- 08-10-2026Last modifiedVulnerability information updated.
Description
Out-of-bounds read in Microsoft Office Word allows an unauthorized attacker to disclose information locally.
CVSS metrics
2 scores · 2 sources · 1 versionMedium 5.5Preferred score · CVE.org (CNA)
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N/E:U/RL:O/RC:CSourcesAll 2 agree
- NVDNIST5.5MediumCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
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 score0.54%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Microsoft14 products
- 365_appsna
- microsoft_365na
- microsoft 365 apps for enterprise≥ 16.0.1, < https://aka.ms/OfficeSecurityReleases
- microsoft office 2019≥ 19.0.0, < https://aka.ms/OfficeSecurityReleases
- microsoft office 365 for mac≥ 1.0.0, < 16.112.26081010
1 vendor · 14 products
