CVE-2026-45491
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Description
A flaw was found in .NET's System.Formats.Tar library. When extracting a specially crafted TAR archive containing symbolic links, the TarFile.ExtractToDirectory() method may incorrectly follow those links and write files outside the intended extraction directory. An attacker could exploit this issue to create or overwrite files in locations accessible to the extracting process, potentially leading to unauthorized file modification.
Statement
This vulnerability affects .NET's TAR archive extraction functionality. Red Hat Product Security has assessed this issue as a Moderate severity vulnerability.
The flaw occurs in System.Formats.Tar when processing TAR archives containing symbolic links. During extraction, the TarFile.ExtractToDirectory() method may incorrectly follow symlink paths and write files outside the intended extraction directory.
Successful exploitation requires a vulnerable application to process a specially crafted TAR archive. An attacker could use this behavior to create or overwrite files in locations accessible to the extracting process, potentially affecting system or application integrity.
The vulnerability is a symlink path traversal issue that results in unauthorized file modification outside the designated extraction directory. The primary security impact is integrity compromise through arbitrary file writes.
Mitigation
Red Hat is not aware of a practical temporary workaround that fully mitigates this issue or meets Red Hat Product Security's standards for usability, deployment, applicability, or stability. Customers are advised to apply the relevant security updates when they become available.
Additional Information
- This content is not included.Bugzilla 2487164: dotnet: .NET: Local file tampering via link following vulnerability
- Content from cwe.mitre.org is not included.CWE-59: Improper Link Resolution Before File Access ('Link Following')
- FAQ: Frequently asked questions about CVE-2026-45491
- 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-2026-45491
Content from nvd.nist.gov is not included.https://nvd.nist.gov/vuln/detail/CVE-2026-45491
Affected Packages and Issued Red Hat Security Errata
| Products / Services | Components | State | Errata |
|---|---|---|---|
| Red Hat Enterprise Linux 10 | dotnet8.0 | Fixed | RHSA-2026:25111 |
| Red Hat Enterprise Linux 10 | dotnet9.0 | Fixed | RHSA-2026:25112 |
| Red Hat Enterprise Linux 10 | dotnet10.0 | Fixed | RHSA-2026:25115 |
| Red Hat Enterprise Linux 10.0 Extended Update Support | dotnet8.0 | Fixed | RHSA-2026:28007 |
| Red Hat Enterprise Linux 10.0 Extended Update Support | dotnet9.0 | Fixed | RHSA-2026:28009 |
| Red Hat Enterprise Linux 8 | dotnet8.0 | Fixed | RHSA-2026:25110 |
| Red Hat Enterprise Linux 8 | dotnet9.0 | Fixed | RHSA-2026:25113 |
| Red Hat Enterprise Linux 8 | dotnet10.0 | Fixed | RHSA-2026:25114 |
| Red Hat Enterprise Linux 9 | dotnet8.0 | Fixed | RHSA-2026:25220 |
| Red Hat Enterprise Linux 9 | dotnet9.0 | Fixed | RHSA-2026:25221 |
| Red Hat Enterprise Linux 9 | dotnet10.0 | Fixed | RHSA-2026:25222 |
| Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions | dotnet8.0 | Fixed | This content is not included.RHSA-2026:28227 |
| Red Hat Enterprise Linux 9.6 Extended Update Support | dotnet8.0 | Fixed | RHSA-2026:28011 |
| Red Hat Hardened Images | dotnet9-0-main | Fixed | RHSA-2026:17527 |
| Red Hat Hardened Images | dotnet10-0-main | Fixed | RHSA-2026:26638 |
| Red Hat Hardened Images | dotnet8-0-main | Fixed | RHSA-2026:26994 |
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 | 6.2 | 5.5 |
| Attack Vector | Local | Local |
| Attack Complexity | Low | Low |
| Privileges Required | None | Low |
| User Interaction | None | None |
| Scope | Unchanged | Unchanged |
| Confidentiality Impact | None | None |
| Integrity Impact | High | High |
| Availability Impact | None | None |
CVSS v3 Vector
Red Hat CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
NVD CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
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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