CVE-2023-36563: Microsoft WordPad Information Disclosure Vulnerability

CVE-2023-36563 is an information disclosure vulnerability in Microsoft WordPad, rated Important by Microsoft, with a CVSS 3.1 base score of 6.5 (Medium). An attacker can exploit it remotely over the network, without any privileges and only if a user takes an action. Microsoft reports that it has been exploited in the wild. It was publicly disclosed before the fix was released. CISA added it to the Known Exploited Vulnerabilities catalog on 10 October 2023, with a remediation deadline of 31 October 2023 for US federal agencies. The EPSS model estimates a 20.32% probability of exploitation activity in the next 30 days, higher than 97% of all scored vulnerabilities. Microsoft released the fix on 10 October 2023 in the October 2023 Patch Tuesday, delivered through 15 security updates (KB5031361, KB5031364, KB5031358, KB5031356 and more). It affects 33 products in 2 product families (Windows, ESU).

Key facts

CVE ID: CVE-2023-36563
Severity: Medium CVSS 6.5
Microsoft severity: Important
Impact: Information Disclosure
Exploited in the wild: Yes
Publicly disclosed: Yes
Exploitation likelihood: Detected
Weakness: CWE-20
EPSS: 20.32% (percentile 97%)
CISA KEV: Listed 10 October 2023, due 31 October 2023
Released: 10 October 2023
Last updated: 11 October 2023
Patch Tuesday: October 2023 Patch Tuesday
Product families: Windows, ESU

CVSS score and vector

Microsoft scores CVE-2023-36563 at 6.5 (temporal 5.9) using CVSS 3.1. Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N/E:P/RL:O/RC:C

Metric	Value
Attack vector	Network
Attack complexity	Low
Privileges required	None
User interaction	Required
Scope	Unchanged
Confidentiality impact	High
Integrity impact	None
Availability impact	None
Exploit code maturity	Proof of concept
Remediation level	Official fix
Report confidence	Confirmed

Frequently asked questions (Microsoft)

According to the CVSS metric, user interaction is required (UI:R). What interaction would the user have to do?

An attacker must send the user a malicious file and convince them to open it.

What type of information could be disclosed by this vulnerability?

Exploiting this vulnerability could allow the disclosure of NTLM hashes.

Affected products (33)

Windows

Product	Security update	Type	Fixed build	Restart
Windows 10 Version 1809 for 32-bit Systems	KB5031361	Security Update	10.0.17763.4974	Yes
Windows 10 Version 1809 for x64-based Systems	KB5031361	Security Update	10.0.17763.4974	Yes
Windows 10 Version 1809 for ARM64-based Systems	KB5031361	Security Update	10.0.17763.4974	Yes
Windows Server 2019	KB5031361	Security Update	10.0.17763.4974	Yes
Windows Server 2019 (Server Core installation)	KB5031361	Security Update	10.0.17763.4974	Yes
Windows Server 2022	KB5031364	Security Update	10.0.20348.2031	Yes
Windows Server 2022 (Server Core installation)	KB5031364	Security Update	10.0.20348.2031	Yes
Windows 11 version 21H2 for x64-based Systems	KB5031358	Security Update	10.0.22000.2538	Yes
Windows 11 version 21H2 for ARM64-based Systems	KB5031358	Security Update	10.0.22000.2538	Yes
Windows 10 Version 21H2 for 32-bit Systems	KB5031356	Security Update	10.0.19041.3570	Yes
Windows 10 Version 21H2 for ARM64-based Systems	KB5031356	Security Update	10.0.19041.3570	Yes
Windows 10 Version 21H2 for x64-based Systems	KB5031356	Security Update	10.0.19041.3570	Yes
Windows 11 Version 22H2 for ARM64-based Systems	KB5031354	Security Update	10.0.22621.2428	Yes
Windows 11 Version 22H2 for x64-based Systems	KB5031354	Security Update	10.0.22621.2428	Yes
Windows 10 Version 22H2 for x64-based Systems
Windows 10 Version 22H2 for ARM64-based Systems
Windows 10 Version 22H2 for 32-bit Systems
Windows 10 for 32-bit Systems	KB5031377	Security Update	10.0.10240.20232	Yes
Windows 10 for x64-based Systems	KB5031377	Security Update	10.0.10240.20232	Yes
Windows 10 Version 1607 for 32-bit Systems	KB5031362	Security Update	10.0.14393.6351	Yes
Windows 10 Version 1607 for x64-based Systems	KB5031362	Security Update	10.0.14393.6351	Yes
Windows Server 2016	KB5031362	Security Update	10.0.14393.6351	Yes
Windows Server 2016 (Server Core installation)	KB5031362	Security Update	10.0.14393.6351	Yes

ESU

Product	Security update	Type	Fixed build	Restart
Windows Server 2008 for 32-bit Systems Service Pack 2	KB5031416 KB5031411	Monthly Rollup Security Only	6.0.6003.22317 6.0.6003.22317	Yes Yes
Windows Server 2008 for 32-bit Systems Service Pack 2 (Server Core installation)	KB5031416 KB5031411	Monthly Rollup Security Only	6.0.6003.22317 6.0.6003.22317	Yes Yes
Windows Server 2008 for x64-based Systems Service Pack 2	KB5031416 KB5031411	Monthly Rollup Security Only	6.0.6003.22317 6.0.6003.22317	Yes Yes
Windows Server 2008 for x64-based Systems Service Pack 2 (Server Core installation)	KB5031416 KB5031411	Monthly Rollup Security Only	6.0.6003.22317 6.0.6003.22317	Yes Yes
Windows Server 2008 R2 for x64-based Systems Service Pack 1	KB5031408 KB5031441	Monthly Rollup Security Only	6.1.7601.26769 6.1.7601.26769	Yes Yes
Windows Server 2008 R2 for x64-based Systems Service Pack 1 (Server Core installation)	KB5031408 KB5031441	Monthly Rollup Security Only	6.1.7601.26769 6.1.7601.26769	Yes Yes
Windows Server 2012	KB5031442 KB5031427	Monthly Rollup Security Only	6.2.9200.24523 6.2.9200.24523	Yes Yes
Windows Server 2012 (Server Core installation)	KB5031442 KB5031427	Monthly Rollup Security Only	6.2.9200.24523 6.2.9200.24523	Yes Yes
Windows Server 2012 R2	KB5031419 KB5031407	Monthly Rollup Security Only	6.3.9600.21620 6.3.9600.21620	Yes Yes
Windows Server 2012 R2 (Server Core installation)	KB5031419 KB5031407	Monthly Rollup Security Only	6.3.9600.21620 6.3.9600.21620	Yes Yes

Security updates (15)

KB5031361 (Security Update)
KB5031364 (Security Update)
KB5031358 (Security Update)
KB5031356 (Security Update)
KB5031354 (Security Update)
KB5031377 (Security Update)
KB5031362 (Security Update)
KB5031416 (Monthly Rollup)
KB5031411 (Security Only)
KB5031408 (Monthly Rollup)
KB5031441 (Security Only)
KB5031442 (Monthly Rollup)
KB5031427 (Security Only)
KB5031419 (Monthly Rollup)
KB5031407 (Security Only)

Exploitation and detection

CISA Known Exploited Vulnerabilities

Date added: 10 October 2023
Federal due date: 31 October 2023
Ransomware use: Unknown
Required action: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

VulnCheck KEV

Date added: 10 October 2023
Ransomware use: Unknown
Independent sources: 1

10 October 2023 · api.msrc.microsoft.com
10 October 2023 · msrc.microsoft.com
10 October 2023 · cisa.gov
9 April 2025 · microsoft.com

NIST NVD data

NVD status: Analyzed
NVD CVSS: 6.5 (MEDIUM)
NVD weakness: CWE-20
Published to NVD: 10 October 2023
NVD last modified: 28 October 2025

Affected configurations (CPE)

Product	Vulnerable versions
windows 10 1507	before 10.0.10240.20232
windows 10 1607 (x64)	before 10.0.14393.6351
windows 10 1607 (x86)	before 10.0.14393.6351
windows 10 1809	before 10.0.17763.4974
windows 10 1809 (arm64)	before 10.0.17763.4974
windows 10 1809 (x64)	before 10.0.17763.4974
windows 10 1809 (x86)	before 10.0.17763.4974
windows 10 21h2	before 10.0.19041.3570
windows 10 22h2	before 10.0.19045.3570
windows 11 21h2	before 10.0.22000.2538
windows 11 22h2	before 10.0.22621.2428
windows server 2008	all listed versions
windows server 2008 r2 (x64)	all listed versions
windows server 2012	all listed versions
windows server 2012 r2	all listed versions
windows server 2016	before 10.0.14393.6351
windows server 2019	before 10.0.17763.4974
windows server 2022	before 10.0.20348.2031

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-36563 (Patch, Vendor Advisory)
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-36563 (Patch, Vendor Advisory)
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-36563 (US Government Resource)

Acknowledgments

Microsoft Threat Intelligence

Revision history

Version	Date	Description
1.0	10 October 2023	Information published.
1.1	11 October 2023	Updated FAQ information. This is an informational change only.