CVE-2026-11812

{"id": "CVE-2026-11812", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-11812", "role": "CISA Coordinator", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "version": "2.0.3", "timestamp": "2026-08-12T18:51:06.812463Z"}}], "cvssMetricV31": [{"type": "Secondary", "source": "vulnerabilities@zephyrproject.org", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 2.5, "attackVector": "LOCAL", "baseSeverity": "LOW", "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "HIGH", "availabilityImpact": "LOW", "privilegesRequired": "LOW", "confidentialityImpact": "NONE"}, "impactScore": 1.4, "exploitabilityScore": 1.0}]}, "affected": [{"source": "vulnerabilities@zephyrproject.org", "affectedData": [{"vendor": "zephyrproject", "product": "zephyr", "versions": [{"status": "affected", "version": "2.0.0", "lessThan": "4.4.2", "versionType": "semver"}], "packageName": "zephyr", "programFiles": ["subsys/mgmt/updatehub/updatehub.c"], "collectionURL": "https://github.com/zephyrproject-rtos/zephyr", "defaultStatus": "unaffected"}]}], "published": "2026-08-10T23:16:51.020", "references": [{"url": "https://github.com/zephyrproject-rtos/zephyr/commit/551d3f92b36e9604f039101c4e4f623682d02159", "source": "vulnerabilities@zephyrproject.org"}, {"url": "https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-vprh-rff6-46xp", "source": "vulnerabilities@zephyrproject.org"}], "vulnStatus": "Awaiting Analysis", "weaknesses": [{"type": "Secondary", "source": "vulnerabilities@zephyrproject.org", "description": [{"lang": "en", "value": "CWE-362"}]}], "descriptions": [{"lang": "en", "value": "The UpdateHub management subsystem (subsys/mgmt/updatehub/updatehub.c) drives every update operation through a single file-scope ctx structure that holds the CoAP block context, payload buffer, status code, socket, and a one-element poll-fd array fds[1]. Access to ctx was not serialized, and prepare_fds() wrote ctx.fds[ctx.nfds] and incremented ctx.nfds with no bounds check.\n\nTwo independent paths mutate ctx concurrently: the background autohandler running on the system workqueue, and user-triggered operations reached through the updatehub run shell command, direct API calls, or \u2014 since the operations are exposed as syscalls \u2014 userspace threads. When a second flow enters prepare_fds() while ctx.nfds is already 1, the write lands one element past the array; by struct layout it overlaps the adjacent ctx.sock/ctx.nfds members. More broadly, the unsynchronized sharing lets two flows interleave connection setup and teardown, double-closing a socket descriptor or scribbling the shared buffers.\n\nThe result is corruption of the update subsystem's internal state and denial of service of the firmware-update path; the out-of-bounds write is contained within the ctx structure and there is no demonstrated path to memory outside it or to code execution. Triggering requires a local actor able to invoke update operations (or, with CONFIG_USERSPACE, an unprivileged userspace thread) and to win a timing race against the background handler; remote peers cannot control the race timing. The fix serializes the entry points with a mutex and adds a bounds check to prepare_fds()."}, {"lang": "es", "value": "El subsistema de gesti\u00f3n de UpdateHub (subsys/mgmt/updatehub/updatehub.c) impulsa cada operaci\u00f3n de actualizaci\u00f3n a trav\u00e9s de una \u00fanica estructura ctx de \u00e1mbito de archivo que contiene el contexto del bloque CoAP, el b\u00fafer de carga \u00fatil, el c\u00f3digo de estado, el socket y un array poll-fd de un elemento fds[1]. El acceso a ctx no estaba serializado, y prepare_fds() escribi\u00f3 ctx.fds[ctx.nfds] e increment\u00f3 ctx.nfds sin una comprobaci\u00f3n de l\u00edmites.\n\nDos rutas independientes mutan ctx concurrentemente: el autogestor en segundo plano ejecut\u00e1ndose en la cola de trabajo del sistema, y operaciones activadas por el usuario a las que se accede a trav\u00e9s del comando de shell updatehub run, llamadas directas a la API, o - dado que las operaciones se exponen como llamadas al sistema (syscalls) - hilos de espacio de usuario. Cuando un segundo flujo entra en prepare_fds() mientras ctx.nfds ya es 1, la escritura se produce un elemento m\u00e1s all\u00e1 del array; por la disposici\u00f3n de la estructura, se superpone a los miembros adyacentes ctx.sock/ctx.nfds. En t\u00e9rminos m\u00e1s generales, el intercambio no sincronizado permite que dos flujos intercalen el establecimiento y la desconexi\u00f3n de la conexi\u00f3n, cerrando dos veces un descriptor de socket o sobrescribiendo los b\u00faferes compartidos.\n\nEl resultado es la corrupci\u00f3n del estado interno del subsistema de actualizaci\u00f3n y la denegaci\u00f3n de servicio de la ruta de actualizaci\u00f3n del firmware; la escritura fuera de l\u00edmites est\u00e1 contenida dentro de la estructura ctx y no hay una ruta demostrada a la memoria fuera de ella o a la ejecuci\u00f3n de c\u00f3digo. El desencadenamiento requiere un actor local capaz de invocar operaciones de actualizaci\u00f3n (o, con CONFIG_USERSPACE, un hilo de espacio de usuario sin privilegios) y de ganar una carrera de tiempo contra el gestor en segundo plano; los pares remotos no pueden controlar el tiempo de la carrera. La soluci\u00f3n serializa los puntos de entrada con un mutex y a\u00f1ade una comprobaci\u00f3n de l\u00edmites a prepare_fds()."}], "lastModified": "2026-10-23T19:10:00.167", "sourceIdentifier": "vulnerabilities@zephyrproject.org"}