CVE-2026-45491
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.
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).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 6.2 | 5.5 | 6.2 |
| Attack Vector | Local | Local | Local |
| Attack Complexity | Low | Low | Low |
| Privileges Required | None | Low | None |
| User Interaction | None | None | None |
| Scope | Unchanged | Unchanged | Unchanged |
| Confidentiality | None | None | None |
| Integrity Impact | High | High | High |
| Availability Impact | None | None | None |
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
cve.org: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N/E:U/RL:O/RC:C
Understanding the Weakness (CWE)
Confidentiality,Integrity,Access Control
Technical Impact: Read Files or Directories; Modify Files or Directories; Bypass Protection Mechanism
An attacker may be able to traverse the file system to unintended locations and read or overwrite the contents of unexpected files. If the files are used for a security mechanism then an attacker may be able to bypass the mechanism.
Other
Technical Impact: Execute Unauthorized Code or Commands
Windows simple shortcuts, sometimes referred to as soft links, can be exploited remotely since a ".LNK" file can be uploaded like a normal file. This can enable remote execution.
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