Vulnerability · Published Mar 3, 2026 · Assigned by GitHub_M
CVE-2026-27905BentoML has an Arbitrary File Write via Symlink Path Traversal in Tar Extraction
High 8.6
In plain English
A high-severity security flaw in BentoML from bentoml. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 22% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
BentoML is a Python library for building online serving systems optimized for AI apps and model inference. Prior to 1.4.36, the safe_extract_tarfile() function validates that each tar member's path is within the destination directory, but for symlink members it only validates the symlink's own path, not the symlink's target. An attacker can create a malicious bento/model tar file containing a symlink pointing outside the extraction directory, followed by a regular file that writes through the symlink, achieving arbitrary file write on the host filesystem. This vulnerability is fixed in 1.4.36.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| PyPI | bentoml | 1.4.36 | GHSA-m6w7-qv66-g3mf |
| PyPI | bentoml | 1.4.36 | PYSEC-2026-2398 |
Affected products (as reported)
Weakness: CWE-59 · Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N