CVE-2026-122518: Microsoft Edge (Chromium-based) Information Disclosure Vulnerability
CVE-2026-122518 is an information disclosure vulnerability in Microsoft Edge (Chromium-based), rated Moderate by Microsoft, with a CVSS 3.1 base score of 6.5 (Medium). An attacker can exploit it remotely over the network, 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. Microsoft released the fix on 4 November 2026, outside Patch Tuesday. It affects 1 product in 1 product family (Browser).
Key facts
- CVE ID
- CVE-2026-122518
- Severity
- Medium CVSS 6.5
- Microsoft severity
- Moderate
- Impact
- Information Disclosure
- Exploited in the wild
- No
- Publicly disclosed
- No
- Exploitation likelihood
- Less Likely
- CISA KEV
- Not listed
- Released
- Last updated
- Patch Tuesday
- November 2026 Patch Tuesday
- Product families
- Browser
CVSS score and vector
Microsoft scores CVE-2026-122518 at 6.5 (temporal 5.7) using CVSS 3.1. Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C
| Metric | Value |
|---|---|
| Attack vector | Network |
| Attack complexity | Low |
| Privileges required | None |
| User interaction | Required |
| Scope | Unchanged |
| Confidentiality impact | High |
| Integrity impact | None |
| Availability impact | None |
| Exploit code maturity | Unproven |
| Remediation level | Official fix |
| Report confidence | Confirmed |
Description
Out-of-bounds read in Microsoft Edge (Chromium-based) allows an unauthorized attacker to disclose information over a network.
Frequently asked questions (Microsoft)
What type of information could be disclosed by this vulnerability?
An attacker who successfully exploited this vulnerability could potentially read small portions of heap memory.
Affected products (1)
Browser
| Product | Security update | Type | Fixed build | Restart |
|---|---|---|---|---|
| Microsoft Edge (Chromium-based) | Release Notes | Security Update | 156.0.4314.42 | No |
Acknowledgments
Revision history
| Version | Date | Description |
|---|---|---|
| 1.0 | Information published. |