CVE-2026-79778
Description
A flaw was found in rclone. In the WebDAV TUS creation handler, a vulnerability allows a malicious or compromised configured endpoint to trigger a denial of service. By resetting connections during TUS uploads, an attacker can cause the application to panic, terminating processes and halting unrelated work. This leads to a complete disruption of service.
Statement
A flaw was found in rclone. When using the WebDAV backend with TUS (resumable upload) support, a nil pointer dereference panic can occur if the server returns a nil HTTP response during a TUS upload operation. A malicious or misconfigured WebDAV server can trigger this condition, causing the rclone process to crash.
Mitigation
Avoid using rclone's WebDAV backend with TUS-enabled servers from untrusted sources. If TUS uploads are not required, use a WebDAV server configuration that does not advertise TUS support.
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 | 5.3 | N/A | 5.3 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | High | N/A | High |
| Privileges Required | None | N/A | None |
| User Interaction | Required | N/A | Required |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | None | N/A | None |
| Integrity Impact | None | N/A | None |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:H
cve.org: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:H
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Crash, Exit, or Restart
NULL pointer dereferences usually result in the failure of the process unless exception handling (on some platforms) is available and implemented. Even when exception handling is being used, it can still be very difficult to return the software to a safe state of operation.
Integrity,Confidentiality
Technical Impact: Execute Unauthorized Code or Commands; Read Memory; Modify Memory
In rare circumstances, when NULL is equivalent to the 0x0 memory address and privileged code can access it, then writing or reading memory is possible, which may lead to code execution.
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