SB2026081148 - Multiple vulnerabilities in Microsoft SharePoint Server
Published: August 11, 2026
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 25 vulnerabilities.
1) Cross-site scripting (CVE-ID: CVE-2026-64897)
CWE-ID: CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVSSv4: 4.8 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N]
The disclosed vulnerability allows a remote attacker to perform cross-site scripting (XSS) attacks.
The vulnerability exists due to insufficient sanitization of user-supplied data in Microsoft SharePoint Server. A remote user can trick the victim to follow a specially crafted link and execute arbitrary HTML and script code in user's browser in context of vulnerable website.
Successful exploitation of this vulnerability may allow a remote attacker to steal potentially sensitive information, change appearance of the web page, perform phishing and drive-by-download attacks.
2) Improper Authentication (CVE-ID: CVE-2026-62827)
CWE-ID: CWE-287 - Improper Authentication
CVSSv4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to bypass authentication process.
The vulnerability exists due to an error in when processing authentication requests in Microsoft SharePoint Server. A remote user can bypass authentication process and gain elevated privileges on the target system.
3) Path traversal (CVE-ID: CVE-2026-62837)
CWE-ID: CWE-22 - Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
CVSSv4: 7.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to perform directory traversal attacks.
The vulnerability exists due to input validation error when processing directory traversal sequences in Microsoft SharePoint Server. A remote user can send a specially crafted HTTP request and read arbitrary files on the system.
4) Deserialization of Untrusted Data (CVE-ID: CVE-2026-63514)
CWE-ID: CWE-502 - Deserialization of Untrusted Data
CVSSv4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to execute arbitrary code on the target system.
The vulnerability exists due to insecure input validation when processing serialized data in Microsoft SharePoint Server. A remote user can pass specially crafted data to the application and execute arbitrary code on the target system.
Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.
5) Incorrect authorization (CVE-ID: CVE-2026-63512)
CWE-ID: CWE-863 - Incorrect Authorization
CVSSv4: 7.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to bypass authorization checks.
The vulnerability exists due to incorrect authorization in Microsoft SharePoint Server. A remote user can perform tampering on the system.
6) Deserialization of Untrusted Data (CVE-ID: CVE-2026-63516)
CWE-ID: CWE-502 - Deserialization of Untrusted Data
CVSSv4: 7.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to compromise the target system.
The vulnerability exists due to insecure input validation when processing serialized data in Microsoft SharePoint Server. A remote user can pass specially crafted data to the application and gain access to sensitive information on the system.
7) Input validation error (CVE-ID: CVE-2026-63520)
CWE-ID: CWE-20 - Improper input validation
CVSSv4: 9.2 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to execute arbitrary code on the target system.
The vulnerability exists due to insufficient validation of user-supplied input in Microsoft SharePoint Server. A remote attacker can pass specially crafted input to the application and execute arbitrary code on the system.
8) Cross-site scripting (CVE-ID: CVE-2026-64922)
CWE-ID: CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVSSv4: 4.8 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N]
The disclosed vulnerability allows a remote attacker to perform cross-site scripting (XSS) attacks.
The vulnerability exists due to insufficient sanitization of user-supplied data in Microsoft SharePoint Server. A remote user can trick the victim to follow a specially crafted link and execute arbitrary HTML and script code in user's browser in context of vulnerable website.
Successful exploitation of this vulnerability may allow a remote attacker to steal potentially sensitive information, change appearance of the web page, perform phishing and drive-by-download attacks.
9) Deserialization of Untrusted Data (CVE-ID: CVE-2026-65658)
CWE-ID: CWE-502 - Deserialization of Untrusted Data
CVSSv4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to execute arbitrary code on the target system.
The vulnerability exists due to insecure input validation when processing serialized data in Microsoft SharePoint Server. A remote user can pass specially crafted data to the application and execute arbitrary code on the target system.
Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.
10) Deserialization of Untrusted Data (CVE-ID: CVE-2026-65663)
CWE-ID: CWE-502 - Deserialization of Untrusted Data
CVSSv4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to execute arbitrary code on the target system.
The vulnerability exists due to insecure input validation when processing serialized data in Microsoft SharePoint Server. A remote user can pass specially crafted data to the application and execute arbitrary code on the target system.
Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.
11) Code Injection (CVE-ID: CVE-2026-65660)
CWE-ID: CWE-94 - Improper Control of Generation of Code ('Code Injection')
CVSSv4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to execute arbitrary code on the target system.
The vulnerability exists due to improper input validation in Microsoft SharePoint Server. A remote user can execute arbitrary code on the target system.
Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.
12) Deserialization of Untrusted Data (CVE-ID: CVE-2026-65665)
CWE-ID: CWE-502 - Deserialization of Untrusted Data
CVSSv4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to execute arbitrary code on the target system.
The vulnerability exists due to insecure input validation when processing serialized data in Microsoft SharePoint Server. A remote user can pass specially crafted data to the application and execute arbitrary code on the target system.
Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.
13) Cross-site scripting (CVE-ID: CVE-2026-70355)
CWE-ID: CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVSSv4: 4.8 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N]
The disclosed vulnerability allows a remote attacker to perform cross-site scripting (XSS) attacks.
The vulnerability exists due to insufficient sanitization of user-supplied data in Microsoft SharePoint Server. A remote user can trick the victim to follow a specially crafted link and execute arbitrary HTML and script code in user's browser in context of vulnerable website.
Successful exploitation of this vulnerability may allow a remote attacker to steal potentially sensitive information, change appearance of the web page, perform phishing and drive-by-download attacks.
14) Cross-site scripting (CVE-ID: CVE-2026-62829)
CWE-ID: CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVSSv4: 4.8 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N]
The disclosed vulnerability allows a remote attacker to perform cross-site scripting (XSS) attacks.
The vulnerability exists due to insufficient sanitization of user-supplied data in Microsoft SharePoint Server. A remote user can trick the victim to follow a specially crafted link and execute arbitrary HTML and script code in user's browser in context of vulnerable website.
Successful exploitation of this vulnerability may allow a remote attacker to steal potentially sensitive information, change appearance of the web page, perform phishing and drive-by-download attacks.
15) Cross-site scripting (CVE-ID: CVE-2026-64900)
CWE-ID: CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVSSv4: 4.8 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N]
The disclosed vulnerability allows a remote attacker to perform cross-site scripting (XSS) attacks.
The vulnerability exists due to insufficient sanitization of user-supplied data in Microsoft SharePoint Server. A remote user can trick the victim to follow a specially crafted link and execute arbitrary HTML and script code in user's browser in context of vulnerable website.
Successful exploitation of this vulnerability may allow a remote attacker to steal potentially sensitive information, change appearance of the web page, perform phishing and drive-by-download attacks.
16) Cross-site scripting (CVE-ID: CVE-2026-64902)
CWE-ID: CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVSSv4: 4.8 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N]
The disclosed vulnerability allows a remote attacker to perform cross-site scripting (XSS) attacks.
The vulnerability exists due to insufficient sanitization of user-supplied data in Microsoft SharePoint Server. A remote user can trick the victim to follow a specially crafted link and execute arbitrary HTML and script code in user's browser in context of vulnerable website.
Successful exploitation of this vulnerability may allow a remote attacker to steal potentially sensitive information, change appearance of the web page, perform phishing and drive-by-download attacks.
17) Deserialization of Untrusted Data (CVE-ID: CVE-2026-64901)
CWE-ID: CWE-502 - Deserialization of Untrusted Data
CVSSv4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to execute arbitrary code on the target system.
The vulnerability exists due to insecure input validation when processing serialized data in Microsoft SharePoint Server. A remote user can pass specially crafted data to the application and execute arbitrary code on the target system.
Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.
18) Cross-site scripting (CVE-ID: CVE-2026-64916)
CWE-ID: CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVSSv4: 4.8 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N]
The disclosed vulnerability allows a remote attacker to perform cross-site scripting (XSS) attacks.
The vulnerability exists due to insufficient sanitization of user-supplied data in Microsoft SharePoint Server. A remote user can trick the victim to follow a specially crafted link and execute arbitrary HTML and script code in user's browser in context of vulnerable website.
Successful exploitation of this vulnerability may allow a remote attacker to steal potentially sensitive information, change appearance of the web page, perform phishing and drive-by-download attacks.
19) Missing Authentication for Critical Function (CVE-ID: CVE-2026-64921)
CWE-ID: CWE-306 - Missing Authentication for Critical Function
CVSSv4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to bypass implemented security restrictions.
The vulnerability exists due to Missing authentication for critical function in Microsoft SharePoint Server. A remote user can gain elevated privileges on the target system.
20) Deserialization of Untrusted Data (CVE-ID: CVE-2026-66805)
CWE-ID: CWE-502 - Deserialization of Untrusted Data
CVSSv4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to execute arbitrary code on the target system.
The vulnerability exists due to insecure input validation when processing serialized data in Microsoft SharePoint Server. A remote user can pass specially crafted data to the application and execute arbitrary code on the target system.
Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.
21) Deserialization of Untrusted Data (CVE-ID: CVE-2026-66808)
CWE-ID: CWE-502 - Deserialization of Untrusted Data
CVSSv4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to execute arbitrary code on the target system.
The vulnerability exists due to insecure input validation when processing serialized data in Microsoft SharePoint Server. A remote user can pass specially crafted data to the application and execute arbitrary code on the target system.
Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.
22) Server-Side Request Forgery (SSRF) (CVE-ID: CVE-2026-70326)
CWE-ID: CWE-918 - Server-Side Request Forgery (SSRF)
CVSSv4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
The disclosed vulnerability allows a remote attacker to perform SSRF attacks.
The vulnerability exists due to insufficient validation of user-supplied input in Microsoft SharePoint Server. A remote user can send a specially crafted HTTP request and trick the application to initiate requests to arbitrary systems.
Successful exploitation of this vulnerability may allow a remote attacker gain eelvated privileges on th target system.
23) Server-Side Request Forgery (SSRF) (CVE-ID: CVE-2026-58639)
CWE-ID: CWE-918 - Server-Side Request Forgery (SSRF)
CVSSv4: 7.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N]
The disclosed vulnerability allows a remote attacker to perform SSRF attacks.
The vulnerability exists due to insufficient validation of user-supplied input in Microsoft SharePoint Server. A remote user can send a specially crafted HTTP request and trick the application to initiate requests to arbitrary systems.
Successful exploitation of this vulnerability may allow a remote attacker gain access to sensitive data, located in the local network or send malicious requests to other servers from the vulnerable system.
24) Insufficiently protected credentials (CVE-ID: CVE-2026-62839)
CWE-ID: CWE-522 - Insufficiently Protected Credentials
CVSSv4: 7.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to gain access to sensitive information.
The vulnerability exists due to insufficiently protected credentials in Microsoft SharePoint Server. A reote user can perform spoofing on the system.
25) Cross-site scripting (CVE-ID: CVE-2026-62917)
CWE-ID: CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVSSv4: 4.8 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N]
The disclosed vulnerability allows a remote attacker to perform cross-site scripting (XSS) attacks.
The vulnerability exists due to insufficient sanitization of user-supplied data in Microsoft SharePoint Server. A remote user can trick the victim to follow a specially crafted link and execute arbitrary HTML and script code in user's browser in context of vulnerable website.
Successful exploitation of this vulnerability may allow a remote attacker to steal potentially sensitive information, change appearance of the web page, perform phishing and drive-by-download attacks.
Remediation
Install update from vendor's website.
References
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-64897
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-62827
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-62837
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-63514
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-63512
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-63516
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-63520
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-64922
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-65658
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-65663
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-65660
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-65665
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-70355
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-62829
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-64900
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-64902
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-64901
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-64916
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-64921
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-66805
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-66808
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-70326
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-58639
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-62839
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-62917