CVE-2026-6475
Description
A flaw was found in PostgreSQL. This vulnerability, related to symlink following in pg_basebackup (plain format) and pg_rewind, allows an origin superuser to overwrite local files. By exploiting this, an attacker could potentially hijack the operating system account. This attack has practical implications if specific actions are taken, such as moving files to a different virtual machine (VM) or snapshotting the VM, between the execution of these commands and the server's restart.
Statement
This MODERATE symlink following vulnerability in PostgreSQL's pg_basebackup and pg_rewind allows an origin superuser to overwrite local files. Exploitation requires local access, high privileges (superuser), and specific intermediate actions before server restart. Impact is high to confidentiality, integrity, and availability if exploited. Affects versions before 18.4, 17.10, 16.14, 15.18, and 14.23.
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 | 6.7 | N/A | 8.8 |
| Attack Vector | Local | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | High | N/A | None |
| User Interaction | None | N/A | Required |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | High | N/A | High |
| Integrity Impact | High | N/A | High |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
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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