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CVE-2025-39926

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: genetlink: fix genl_bind() invoking bind() after -EPERM Per family bind/unbind callbacks were introduced to allow families to track multicast group consumer presence, e.g. to start or stop producing events depending on listeners. However, in genl_bind() the bind() callback was invoked even if capability checks failed and ret was set to -EPERM. This means that callbacks could run on behalf of unauthorized callers while the syscall still returned failure to user space. Fix this by only invoking bind() after "if (ret) break;" check i.e. after permission checks have succeeded.

Severity
MEDIUM
CVSS score
5.5 (v3.1)
Vulnerability status
Modified
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2025-10-01 08:15:35.977000
Last modified
2026-10-19 21:10:00.160000
View original CVE JSON 
{
  "id": "CVE-2025-39926",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2025-10-01T08:15:35.977",
  "lastModified": "2026-10-19T21:10:00.160",
  "vulnStatus": "Modified",
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    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ngenetlink: fix genl_bind() invoking bind() after -EPERM\n\nPer family bind/unbind callbacks were introduced to allow families\nto track multicast group consumer presence, e.g. to start or stop\nproducing events depending on listeners.\n\nHowever, in genl_bind() the bind() callback was invoked even if\ncapability checks failed and ret was set to -EPERM. This means that\ncallbacks could run on behalf of unauthorized callers while the\nsyscall still returned failure to user space.\n\nFix this by only invoking bind() after \"if (ret) break;\" check\ni.e. after permission checks have succeeded."
    },
    {
      "lang": "es",
      "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\ngenetlink: corrige la invocación de bind() por genl_bind() después de -EPERM\n\nLas devoluciones de llamada de bind/unbind por familia fueron introducidas para permitir a las familias rastrear la presencia de consumidores de grupos de multidifusión, por ejemplo, para iniciar o detener la producción de eventos dependiendo de los oyentes.\n\nSin embargo, en genl_bind() la devolución de llamada bind() fue invocada incluso si las comprobaciones de capacidad fallaron y ret se estableció en -EPERM. Esto significa que las devoluciones de llamada podrían ejecutarse en nombre de llamadores no autorizados mientras la llamada al sistema aún devolvía un fallo al espacio de usuario.\n\nEsto se corrige invocando bind() solo después de la comprobación 'if (ret) break;', es decir, después de que las comprobaciones de permisos hayan tenido éxito."
    }
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