SB2026061097 - Multiple vulnerabilities in Microsoft Outlook and Word

Description

This security bulletin contains information about 3 vulnerabilities.

1) Type Confusion (CVE-ID: CVE-2026-45456)

CWE-ID: CWE-843 - Type confusion

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to a type confusion error in Microsoft Outlook and Word. A remote attacker can pass specially crafted data to the application, trigger a type confusion error and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

2) Heap-based buffer overflow (CVE-ID: CVE-2026-47635)

CWE-ID: CWE-122 - Heap-based Buffer Overflow

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to a boundary error in Microsoft Outlook and Word. A remote attacker can pass specially crafted data to the application, trigger a heap-based buffer overflow and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

3) Use-after-free (CVE-ID: CVE-2026-45458)

CWE-ID: CWE-416 - Use After Free

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber

The vulnerability allows a remote attacker to compromise vulnerable system.

The vulnerability exists due to a use-after-free error in Microsoft Outlook and Word. A remote attacker can execute arbitrary code on the target system.

Remediation

Install update from vendor's website.

References

• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-45456
• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-47635
• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-45458