CVE-2025-26646
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Description
A flaw was found in .NET and Visual Studio. This vulnerability allows an attacker to use specially crafted input to spoof trusted content or identities, potentially misleading users or systems. This issue requires user interaction and limited privileges but can lead to unauthorized actions or escalation due to incorrect identity or content validation handling.
Statement
This vulnerability in .NET is Important because it allows spoofing of trusted identities or content through crafted input, exploiting weaknesses in validation logic. While it requires user interaction and limited privileges, it can subvert authentication flows or integrity checks, leading to unauthorized actions. In security-sensitive contexts—like signed assembly loading, secure package feeds, or automated build systems—such spoofing can compromise trust boundaries and facilitate privilege escalation or supply chain attacks, making it more severe than a typical moderate flaw.
.NET 6.0 for RHEL-8, RHEL-9 and RHIVOS has reached its End of Life as of November 12, 2024, and is no longer supported. No fixes will be provided for this stream. For additional information about lifecycle for .NET on Red Hat Enterprise Linux, please refer to: https://access.redhat.com/support/policy/updates/net-core.
Mitigation
No mitigation is currently available that meets Red Hat Product Security’s standards for usability, deployment, applicability, or stability.
Additional Information
- This content is not included.Bugzilla 2365317: dotnet: .NET and Visual Studio Spoofing Vulnerability
- Content from cwe.mitre.org is not included.CWE-290: Authentication Bypass by Spoofing
- FAQ: Frequently asked questions about CVE-2025-26646
- Offline Security Data data is available for integration with other systems. See Offline Security Data API to get started.
External References
Content from www.cve.org is not included.https://www.cve.org/CVERecord?id=CVE-2025-26646
Content from nvd.nist.gov is not included.https://nvd.nist.gov/vuln/detail/CVE-2025-26646
Affected Packages and Issued Red Hat Security Errata
| Products / Services | Components | State | Errata |
|---|---|---|---|
| Red Hat Enterprise Linux 10 | dotnet8.0 | Fixed | RHSA-2025:7599 |
| Red Hat Enterprise Linux 10 | dotnet9.0 | Fixed | RHSA-2025:7601 |
| Red Hat Enterprise Linux 8 | dotnet9.0 | Fixed | RHSA-2025:7571 |
| Red Hat Enterprise Linux 8 | dotnet8.0 | Fixed | RHSA-2025:7589 |
| Red Hat Enterprise Linux 9 | dotnet8.0 | Fixed | RHSA-2025:7598 |
| Red Hat Enterprise Linux 9 | dotnet9.0 | Fixed | RHSA-2025:7600 |
| Red Hat Enterprise Linux 9 | dotnet6.0 | Out of support scope | |
| Red Hat Enterprise Linux 9 | dotnet7.0 | Out of support scope | |
| Red Hat Enterprise Linux 9.4 Extended Update Support | dotnet8.0 | Fixed | RHSA-2025:7603 |
Common Vulnerability Scoring System (CVSS) Score Details
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 Authorities (CNA) source for its products and services (see Red Hat classifications ).
| CVSS v3 Score Breakdown | Red Hat | NVD |
|---|---|---|
| CVSS v3 Base Score | 8 | |
| Attack Vector | Network | |
| Attack Complexity | Low | |
| Privileges Required | Low | |
| User Interaction | Required | |
| Scope | Unchanged | |
| Confidentiality Impact | High | |
| Integrity Impact | High | |
| Availability Impact | High |
CVSS v3 Vector
Red Hat CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H
Frequently Asked Questions
Why is Red Hat's CVSS v3 score or Impact different from other vendors?
For more information, see https://access.redhat.com/solutions/762393.
My product is listed as "Under investigation" or "Affected", when will Red Hat release a fix for this vulnerability?
- "Under investigation" doesn't necessarily mean that the product is affected by this vulnerability. It only means that our Analysis Team is still working on determining whether the product is affected and how it is affected.
- "Affected" means that our Analysis Team has determined that this product is affected by this vulnerability and might release a fix to address this in the near future.
What can I do if my product is listed as "Will not fix"?
Available options depend mostly on the Impact of the vulnerability and the current Life Cycle phase of your product. Overall, you have the following options:
- Upgrade to a supported product version that includes a fix for this vulnerability (recommended).
- Apply a mitigation (if one exists).
- Open a This content is not included.support case to request a prioritization of releasing a fix for this vulnerability.
What can I do if my product is listed as "Fix deferred"?
Available options depend mostly on the Impact of the vulnerability and the current Life Cycle phase of your product. Overall, you have the following options:
- Apply a mitigation (if one exists).
- Open a This content is not included.support case to request a prioritization of releasing a fix for this vulnerability.
- Red Hat Engineering focuses on addressing high-priority issues based on their complexity or limited lifecycle support. Therefore, lower-priority issues will not receive immediate fixes.
What is a mitigation?
I have a Red Hat product but it is not in the above list, is it affected?
Why is my security scanner reporting my product as vulnerable to this vulnerability even though my product version is fixed or not affected?
My product is listed as "Out of Support Scope". What does this mean?
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