CVE-2026-27905

BentoML has an Arbitrary File Write via Symlink Path Traversal in Tar Extraction

Published Mar 3, 2026 CVSS 4.0 · 8.6 High EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-m6w7-qv66-g3mf BentoML Vulnerable to Arbitrary File Write via Symlink Path Traversal in Tar Extraction
History
Type Values Removed Values Added
CPEs cpe:2.3:a:bentoml:bentoml:*:*:*:*:*:*:*:*
Metrics cvssV3_1

{'score': 7.8, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H'}

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Bentoml
Bentoml bentoml
Vendors & Products Bentoml
Bentoml bentoml
Type Values Removed Values Added
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.
Title BentoML has an Arbitrary File Write via Symlink Path Traversal in Tar Extraction
Weaknesses CWE-59
References
Metrics cvssV4_0

{'score': 8.6, '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'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Mar 4, 2026, 9:23 PM
Reserved
Feb 24, 2026, 3:19 PM
Status
Analyzed
Published
Mar 3, 2026, 11:15 PM
Modified
Oct 7, 2026, 8:10 AM