CVE-2025-21326: Internet Explorer Remote Code Execution Vulnerability
CVE-2025-21326 is a remote code execution vulnerability in Internet Explorer, rated Important by Microsoft, with a CVSS 3.1 base score of 7.8 (High). An attacker can exploit it by an attacker with local access, without any privileges and only if a user takes an action. Microsoft has not reported exploitation in the wild and rates exploitation as less likely. The EPSS model estimates a 1.37% probability of exploitation activity in the next 30 days, higher than 72% of all scored vulnerabilities. Microsoft released the fix on 14 January 2025 in the January 2025 Patch Tuesday, delivered through 2 security updates (KB5050009, KB5049984). It affects 3 products in 1 product family (Windows).
Key facts
- CVE ID
- CVE-2025-21326
- Severity
- High CVSS 7.8
- Microsoft severity
- Important
- Impact
- Remote Code Execution
- Exploited in the wild
- No
- Publicly disclosed
- No
- Exploitation likelihood
- Less Likely
- Weakness
- CWE-843
- EPSS
- 1.37% (percentile 72%)
- CISA KEV
- Not listed
- Released
- Last updated
- Patch Tuesday
- January 2025 Patch Tuesday
- Product families
- Windows
CVSS score and vector
Microsoft scores CVE-2025-21326 at 7.8 (temporal 6.8) using CVSS 3.1. Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
| Metric | Value |
|---|---|
| Attack vector | Local |
| Attack complexity | Low |
| Privileges required | None |
| User interaction | Required |
| Scope | Unchanged |
| Confidentiality impact | High |
| Integrity impact | High |
| Availability impact | High |
| Exploit code maturity | Unproven |
| Remediation level | Official fix |
| Report confidence | Confirmed |
Frequently asked questions (Microsoft)
According to the CVSS metric, the attack vector is local (AV:L). Why does the CVE title indicate that this is a remote code execution?
The word Remote in the title refers to the location of the attacker. This type of exploit is sometimes referred to as Arbitrary Code Execution (ACE). The attack itself is carried out locally.
For example, when the score indicates that the Attack Vector is Local and User Interaction is Required, this could describe an exploit in which an attacker, through social engineering, convinces a victim to download and open a specially crafted file from a website which leads to a local attack on their computer.
According to the CVSS metrics, successful exploitation of this vulnerability could lead to major loss of confidentiality (C:H), integrity (I:H), and availability (A:H). What does that mean for this vulnerability?
An attacker who successfully exploited this vulnerability could gain high privileges, which include read, write, and delete functionality.
Affected products (3)
Windows
Security updates (2)
NIST NVD data
- NVD status
- Analyzed
- NVD CVSS
- 7.8 (HIGH)
- NVD weakness
- CWE-843
- Published to NVD
- NVD last modified
Affected configurations (CPE)
| Product | Vulnerable versions |
|---|---|
| windows server 2022 23h2 | before 10.0.25398.1369 |
| windows server 2025 | before 10.0.26100.2894 |
References
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-21326 (Patch, Vendor Advisory)
Acknowledgments
Revision history
| Version | Date | Description |
|---|---|---|
| 1.0 | Information published. |