CVE-2026-70188
Description
Inconsistent interpretation of http requests ('http request/response smuggling') in ASP.NET Core allows an unauthorized attacker to bypass a security feature over a network.
Statement
This vulnerability is rated as Critical severity for Red Hat products because an unauthenticated remote attacker can exploit HTTP/2 header parsing flaws over network connections without privileges or user interaction, potentially leading to security control bypasses and HTTP request smuggling. ASP.NET Core applications running on Red Hat Enterprise Linux that use Kestrel as a public-facing web server handling HTTP/2 connections are directly exposed. Services utilizing HTTP/1.1 exclusively or processing pre-validated traffic are not exposed to the specific HTTP/2 HPACK parsing flaws.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
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 | 9.1 | N/A | 9.1 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | High | N/A | High |
| Integrity Impact | High | N/A | High |
| Availability Impact | None | N/A | None |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/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)
Integrity
Technical Impact: Modify Application Data
Frequently Asked Questions
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