CVE-2026-45695
Description
A flaw was found in Kopia, a cross-platform backup tool. An unauthenticated remote attacker can exploit the HTTP server, when started without a password, by sending specially crafted requests to the /api/v1/repo/exists endpoint. This allows the attacker to forward malicious SFTP storage configurations, which can lead to arbitrary code execution through OpenSSH commands.
Statement
Red Hat Product Security considers this bug as Moderate as this requires active change of out of box configaration for this bug to be exploitable. There is no common use case under which Kopia HTTP server should be started without a password.
The diecrepancy in CVSS scores between Red Hat and NVD comes from the differences in User Interaction, Integrity and Availability. The core bug is merely an unintended information disclosure problem if exploited correctly. There is no way to launch a denial of service or affect the integrity of the service. Therefore the bug is scored lower.
Mitigation
This bug can be rendered unusable by making sure that --without-password is not included in startup options for Kopia HTTP server.
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 | 6.5 | N/A | 9.8 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | Required | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | High | N/A | High |
| Integrity Impact | None | N/A | High |
| Availability Impact | None | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Understanding the Weakness (CWE)
Confidentiality,Integrity,Availability,Non-Repudiation
Technical Impact: Execute Unauthorized Code or Commands; DoS: Crash, Exit, or Restart; Read Files or Directories; Modify Files or Directories; Read Application Data; Modify Application Data; Hide Activities
Attackers could execute unauthorized operating system commands, which could then be used to disable the product, or read and modify data for which the attacker does not have permissions to access directly. Since the targeted application is directly executing the commands instead of the attacker, any malicious activities may appear to come from the application or the application's owner.
Frequently Asked Questions
Not sure what something means? Check out our Security Glossary.
Want to get errata notifications? Sign up here.
