CVE-2026-63521Patch(microsoft / 365_apps)

LOWCVSS 5.5 · MEDIUM

Signal is active with 1 mentions in latest observed window

Immediate actions

Patch microsoft 365_apps systems immediately

Recommended action window: Monitor and triage in normal cycle

NVD description

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

microsoft CVEs Back to dashboard

1.0/ 10 priority

Sources & remediation

Patch / fix

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-63521

Weakness type (CWE)

CWE-125

Priority

LOW

Exploitation

NONE

PoC

NONE

Patch

AVAILABLE

Momentum

NONE

Are you affected?

If you run products in this scope, you should treat this CVE as relevant to your environment.

365_apps
office_2019
office_2021
office_2024

Threat summary

Patch or workaround signal is available
1 mentions across 1 observed day

What's happening

Patch or workaround mentioned in 1 signal
1 total mentions across 1 day

Affected systems

Vendors

microsoft

Products

365_appsoffice_2019office_2021office_2024word

2 versions affected across 5 products

Deep dive

Activity timeline1 mentions / 1d

Signal classification1 categories

Patch

1100.0%

Referenced assets1 URL

By indicator

https://windowsforum.com/security-alerts.84/cve-2026-63521-patch-word-information-disclosure-flaw.442674/?utm_source=x&utm_medium=social&utm_campaign=news_node84

Full discourse1 post

Windows Forum@windowsforum46d
Patch
🔐 Word gets an information-disclosure fix, but Microsoft’s public details are thinner than a “please reboot” prompt. Patch Office anyway—mystery is not a security strategy. https://windowsforum.com/security-alerts.84/cve-2026-63521-patch-word-information-disclosure-flaw.442674/?utm_source=x&utm_medium=social&utm_campaign=news_node84 #Office2019 #MicrosoftWord #OfficeSecurityUpdates #Cve202663521 https://t.co/7hcY3YjlzZ
Post summary
The post urges users to patch Office 2019 to resolve an information‑disclosure flaw, referencing a patch URL, but lacks detailed technical or exploit information.
0000039
1.3K followersView on X

CPE platform detail10 entries

Part:

Vendor:

Product:

Version:

Target SW:

Target HW:

10 of 10 entries

Part	Vendor	Product	Version	Target SW	Target HW
App	microsoft	365_apps	-	-	x64
App	microsoft	365_apps	-	-	x86
App	microsoft	office_2019	-	-	x64
App	microsoft	office_2019	-	-	x86
App	microsoft	office_2021	-	-	x64
App	microsoft	office_2021	-	-	x86
App	microsoft	office_2024	-	-	x64
App	microsoft	office_2024	-	-	x86
App	microsoft	word	2016	-	x64
App	microsoft	word	2016	-	x86

Explore more

Back to dashboard microsoft CVEs 365_apps vulnerabilities