CVE-2026-118747: .NET Denial of Service Vulnerability
CVE-2026-118747 is a denial of service vulnerability in .NET, rated Important by Microsoft, with a CVSS 3.1 base score of 7.5 (High). An attacker can exploit it remotely over the network, without any privileges and without user interaction. Microsoft has not reported exploitation in the wild and rates exploitation as less likely. Microsoft released the fix on 10 November 2026 in the November 2026 Patch Tuesday. It affects 4 products in 1 product family (Other).
Key facts
- CVE ID
- CVE-2026-118747
- Severity
- High CVSS 7.5
- Microsoft severity
- Important
- Impact
- Denial of Service
- Exploited in the wild
- No
- Publicly disclosed
- No
- Exploitation likelihood
- Less Likely
- Weakness
- CWE-407
- CISA KEV
- Not listed
- Released
- Last updated
- Patch Tuesday
- November 2026 Patch Tuesday
- Product families
- Other
CVSS score and vector
Microsoft scores CVE-2026-118747 at 7.5 (temporal 6.5) using CVSS 3.1. Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C
| Metric | Value |
|---|---|
| Attack vector | Network |
| Attack complexity | Low |
| Privileges required | None |
| User interaction | None |
| Scope | Unchanged |
| Confidentiality impact | None |
| Integrity impact | None |
| Availability impact | High |
| Exploit code maturity | Unproven |
| Remediation level | Official fix |
| Report confidence | Confirmed |
Description
Inefficient algorithmic complexity in .NET allows an unauthorized attacker to deny service over a network.
Affected products (4)
Other
| Product | Security update | Type | Fixed build | Restart |
|---|---|---|---|---|
| System.Formats.Cbor | Release Notes | Security Update | 9.0.24 | |
| System.Formats.Cbor on .NET 8.0 | Release Notes | Security Update | 8.0.2 | |
| System.Formats.Cbor on .NET 10.0 | Release Notes | Security Update | 10.0.15 | |
| System.Formats.Cbor on .NET 11.0 | Release Notes | Security Update | 11.0.0 |
NIST NVD data
- NVD status
- Awaiting Analysis
- NVD CVSS
- 7.5 (HIGH)
- NVD weakness
- CWE-407
- Published to NVD
- NVD last modified
References
Acknowledgments
- Anonymous
Revision history
| Version | Date | Description |
|---|---|---|
| 1.0 | Information published. | |
| 2.0 | Changes made to the security updates links and information. This is an informational change only. |