CVE-2026-88097: Microsoft Edge (Chromium-based) Elevation of Privilege Vulnerability
CVE-2026-88097 is an edge - chromium vulnerability in Microsoft Edge (Chromium-based), rated Important by Microsoft, with a CVSS 3.1 base score of 8.1 (High). An attacker can exploit it by an attacker with local access, without any privileges and without user interaction. Microsoft has not reported exploitation in the wild and rates exploitation as less likely. The EPSS model estimates a 0.26% probability of exploitation activity in the next 30 days, higher than 17% of all scored vulnerabilities. Microsoft released the fix on 18 September 2026, outside Patch Tuesday. It affects 1 product in 1 product family (Browser).
Key facts
- CVE ID
- CVE-2026-88097
- Severity
- High CVSS 8.1
- Microsoft severity
- Important
- Impact
- Edge - Chromium
- Exploited in the wild
- No
- Publicly disclosed
- No
- Exploitation likelihood
- Less Likely
- Weakness
- CWE-416
- EPSS
- 0.26% (percentile 17%)
- CISA KEV
- Not listed
- Released
- Last updated
- Patch Tuesday
- September 2026 Patch Tuesday
- Product families
- Browser
CVSS score and vector
Microsoft scores CVE-2026-88097 at 8.1 (temporal 7.1) using CVSS 3.1. Vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H/E:U/RL:O/RC:C
| Metric | Value |
|---|---|
| Attack vector | Local |
| Attack complexity | High |
| Privileges required | None |
| User interaction | None |
| Scope | Changed |
| Confidentiality impact | High |
| Integrity impact | High |
| Availability impact | High |
| Exploit code maturity | Unproven |
| Remediation level | Official fix |
| Report confidence | Confirmed |
Description
Use after free in Microsoft Edge (Chromium-based) allows an unauthorized attacker to elevate privileges locally.
Frequently asked questions (Microsoft)
According to the CVSS metric, the attack complexity is high (AC:H). What does that mean for this vulnerability?
For an attacker to exploit this vulnerability, they would need to have knowledge of a specific operation that triggers a memory allocation failure, specifically a use after free.
What privileges could be gained by an attacker who successfully exploited the vulnerability?
An attacker could use this vulnerability to elevate privileges from a Low Integrity Level in a contained ("sandboxed") execution environment to a Medium Integrity Level. Please refer to AppContainer isolation and Mandatory Integrity Control for more information.
According to the CVSS metric, a successful exploitation could lead to a scope change (S:C). What does this mean for this vulnerability?
This vulnerability could lead to a browser sandbox escape.
There are multiple update packages available for some of the affected software. Do I need to install all the updates listed in the Security Updates table for the software?
Yes. Customers should apply all updates offered for the software installed on their systems.
Affected products (1)
Browser
| Product | Security update | Type | Fixed build | Restart |
|---|---|---|---|---|
| Microsoft Edge (Chromium-based) | Release Notes Release Notes | Security Update Security Update | 153.0.4234.46 155.0.4283.45 | No No |
NIST NVD data
- NVD status
- Analyzed
- NVD CVSS
- 8.1 (HIGH)
- NVD weakness
- CWE-416
- Published to NVD
- NVD last modified
Affected configurations (CPE)
| Product | Vulnerable versions |
|---|---|
| edge chromium | before 153.0.4234.46 |
References
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-88097 (Vendor Advisory)
Acknowledgments
Revision history
| Version | Date | Description |
|---|---|---|
| 1.0 | Information published. | |
| 2.0 | Added Edge software to the Security Updates table. Customers that are running supported version of Edge are encouraged to update to the indicated version to be protected from this vulnerability. |