CVE-2026-118746
Description
Not failing securely ('failing open') in .NET allows an unauthorized attacker to bypass a security feature over a network.
What kind of security feature could be bypassed by successfully exploiting this vulnerability? The authentication feature could be bypassed as this vulnerability allows impersonation.
According to the CVSS metric, the attack complexity is high (AC:H). What does that mean for this vulnerability? The attacker must inject themselves into the logical network path between the target and the resource requested by the victim to read or modify network communications. This is called a machine-in-the-middle (MITM) attack.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 6.8 | N/A | 6.8 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | High | N/A | High |
| Privileges Required | None | N/A | None |
| User Interaction | Required | N/A | Required |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | High | N/A | High |
| Integrity Impact | High | N/A | High |
| Availability Impact | None | N/A | None |
| score_breakdown_labels.null | N/A | N/A | N/A |
| score_breakdown_labels.null | N/A | N/A | N/A |
| score_breakdown_labels.null | N/A | N/A | N/A |
Vector
Red Hat: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N/E:U/RL:O/RC:C
cve.org: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N/E:U/RL:O/RC:C
Red Hat CVSS v3 Score Explanation
Microsoft CNA CVSS from pre-release advisory
Understanding the Weakness (CWE)
Other
Technical Impact: Varies by Context
By entering a less secure state, the product inherits the weaknesses associated with that state, making it easier to compromise. At the least, it causes administrators to have a false sense of security.
Access Control
Technical Impact: Bypass Protection Mechanism
Intended access restrictions can be bypassed, which is often contradictory to what the product's administrator expects.
Frequently Asked Questions
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