Multiple vulnerabilities in Microsoft Internet Explorer MapUrlToZone security feature

1) Improper Resolution of Path Equivalence

EUVDB-ID: #VU102636

Risk: Low

CVSSv4.0: 1.2 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2025-21268

CWE-ID: CWE-41 - Improper Resolution of Path Equivalence

Exploit availability: No

Description

The vulnerability allows a remote attacker to gain access to sensitive information.

The vulnerability exists due to improper resolution of path equivalence in MapUrlToZone security feature. A remote attacker can trick the victim into opening a specially crafted file and gain access to sensitive information.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Microsoft Internet Explorer: 11 - 11.1790.17763.0

Windows Server: 2008 R2 6.1.7601.27117 - 2025 10.0.26100.2605

Windows: 10 21H2 10.0.19041.3920 - 11 24H2 10.0.26100.2894

CPE2.3

External links

https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2025-21268

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

How the attacker can exploit this vulnerability?

The attacker would have to trick the victim to visit a specially crafted website.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

2) Improper Resolution of Path Equivalence

EUVDB-ID: #VU102644

Risk: Low

CVSSv4.0: 1.2 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2025-21189

CWE-ID: CWE-41 - Improper Resolution of Path Equivalence

Exploit availability: No

Description

The vulnerability allows a remote attacker to gain access to sensitive information.

The vulnerability exists due to improper resolution of path equivalence in MapUrlToZone security feature. A remote attacker can trick the victim into opening a specially crafted file and gain access to sensitive information.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Microsoft Internet Explorer: 11 - 11.1790.17763.0

Windows: 10 21H2 10.0.19041.3920 - 11 24H2 10.0.26100.2605

Windows Server: 2008 R2 6.1.7601.27117 - 2022 23H2 10.0.25398.1308

CPE2.3

External links

https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2025-21189

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

How the attacker can exploit this vulnerability?

The attacker would have to trick the victim to visit a specially crafted website.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

3) Improper Resolution of Path Equivalence

EUVDB-ID: #VU102645

Risk: Low

CVSSv4.0: 1.2 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2025-21332

CWE-ID: CWE-41 - Improper Resolution of Path Equivalence

Exploit availability: No

Description

The vulnerability allows a remote attacker to gain access to sensitive information.

The vulnerability exists due to improper resolution of path equivalence in MapUrlToZone security feature. A remote attacker can trick the victim into opening a specially crafted file and gain access to sensitive information.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Microsoft Internet Explorer: 11 - 11.1790.17763.0

Windows Server: 2008 R2 6.1.7601.27117 - 2025 10.0.26100.2605

Windows: 10 21H2 10.0.19041.3920 - 11 24H2 10.0.26100.2894

CPE2.3

External links

https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2025-21332

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

How the attacker can exploit this vulnerability?

The attacker would have to trick the victim to visit a specially crafted website.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

4) Integer underflow

EUVDB-ID: #VU102649

Risk: Low

CVSSv4.0: 1.2 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2025-21276

CWE-ID: CWE-191 - Integer underflow

Exploit availability: No

Description

The vulnerability allows a remote attacker to crash the browser.

The vulnerability exists due to integer underflow when handling HTML content in MapUrlToZone security feature. A remote attacker can trick the victim into opening a specially crafted HTML file, trigger an integer underflow and crash the browser.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Microsoft Internet Explorer: 11 - 11.1790.17763.0

Windows Server: 2008 R2 6.1.7601.27117 - 2025 10.0.26100.2605

Windows: 10 21H2 10.0.19041.3920 - 11 24H2 10.0.26100.2894

CPE2.3

External links

https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2025-21276

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

How the attacker can exploit this vulnerability?

The attacker would have to trick the victim to visit a specially crafted website.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

Risk	Low
Patch available	YES
Number of vulnerabilities	4
CVE-ID	CVE-2025-21268 CVE-2025-21189 CVE-2025-21332 CVE-2025-21276
CWE-ID	CWE-41 CWE-191
Exploitation vector	Network
Public exploit	N/A
Vulnerable software	Microsoft Internet Explorer Client/Desktop applications / Web browsers Windows Server Operating systems & Components / Operating system Windows Operating systems & Components / Operating system
Vendor	Microsoft