CVE-2026-40610
BentoML has Information Disclosure in `bentoml build` via symlink traversal in the build context
- Published
- Updated
- Reserved
- Assigned by
- GitHub_M
Description
BentoML is a Python library for building online serving systems optimized for AI apps and model inference. In versions 1.4.38 and prior, the build packaging workflow follows attacker-controlled symlinks inside the build context and copies the referenced file contents into the generated Bento artifact. If a victim builds an untrusted repository or other attacker-supplied build context, the attacker can place a symlink such as loot.txt -> /tmp/outside-marker.txt or a link to a more sensitive local file. When bentoml build runs, BentoML dereferences the symlink and packages the target file contents into the Bento. The leaked file can then propagate further through export, push, or containerization workflows. An attacker can exfiltrate local files from the build host into the Bento artifact, exposing secrets such as cloud credentials, SSH keys, API tokens, environment files, or other sensitive local configurations. Because Bento artifacts are commonly exported, uploaded, stored, or containerized after build, the leaked file contents can spread beyond the original build machine. This issue has been fixed in version 1.4.39.
Public exploit
A reference of the record is tagged as an exploit or proof of concept: anyone can try it against an unpatched system. CISA's SSVC rates its exploitation: a proof of concept is public.
- https://github.com/bentoml/BentoML/security/advisories/GHSA-mcfx-4vc6-qgxv (opens in a new tab)x_refsource_CONFIRMexploit
Timeline
ID reserved
By GitHub_M
- 38 days later
· 38 days later
Published
- 4 days later
· 4 days later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | Medium5.5 | CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N |
| NVDNVD · Analyzed | 3.1 | Medium5.5 | CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N |
- EPSS (exploitation in 30 days)
- 0.28% · top 79% of all CVEs (7 Nov 2026)
- CISA SSVC
- Exploitation: poc · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.5.
Weakness
Affected products
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- PyPIbentomlGHSA-mcfx-4vc6-qgxv (opens in a new tab)
References (3)
- https://github.com/bentoml/BentoML/security/advisories/GHSA-mcfx-4vc6-qgxv (opens in a new tab)x_refsource_CONFIRMexploit
- https://github.com/bentoml/BentoML/commit/5fb7cd41f92e2a56b45391284cf15b9ac9963a1f (opens in a new tab)x_refsource_MISC
- https://github.com/bentoml/BentoML/releases/tag/v1.4.39 (opens in a new tab)x_refsource_MISC
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-mcfx-4vc6-qgxv (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2026-40610)Record last updated .