CVE-2026-91771
Description
A flaw was found in Weights & Biases wandb. This vulnerability allows attackers controlling the backend to supply file names with directory traversal sequences during file download operations. This can lead to writing files outside the intended download directory, potentially enabling arbitrary code execution through modification of shell startup files or Python import paths.
Statement
An IMPORTANT-severity path traversal flaw was found in the Weights & Biases (wandb) client. The File.download function does not validate file names returned by the backend server, so an attacker who controls the backend (for example, a malicious or compromised W&B server) can supply file names containing directory traversal sequences. When a user initiates a download from such a backend, the file is written outside the intended download directory, which can lead to arbitrary code execution, for example through modification of shell startup files or Python import paths. Red Hat products are affected through the wandb Python dependency: Red Hat AI Inference Server (rhaiis/vllm-cpu-rhel9 and rhaiis/vllm-tpu-rhel9 containers) and the Exploit Intelligence vulnerability-analysis-rhel9 container bundle affected wandb versions. The resolution for these affected products is delegated to the respective product streams, which assessed that a fix will not be pursued; the residual risk is limited to users who download files through a wandb client connected to a backend controlled by an attacker. Red Hat's severity (CVSS 8.8, CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H) is consistent with the upstream CVSS v3.1 score, while the upstream CVSS v4.0 score is 8.7.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability. The upstream project addressed this issue in wandb 0.29.0; updating the bundled wandb dependency to a fixed upstream version would address the issue in the affected Red Hat products.
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 | 8.8 | N/A | 8.8 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | Required | 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:N/AC:L/PR:N/UI:R/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
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