Intel

CVE-2026-31411

Linux kernel (Xilinx) vulnerabilities

mediumEPSS 0.1%

Description

In the Linux kernel, the following vulnerability has been resolved: net: atm: fix crash due to unvalidated vcc pointer in sigd_send() Reproducer available at [1]. The ATM send path (sendmsg -> vcc_sendmsg -> sigd_send) reads the vcc pointer from msg->vcc and uses it directly without any validation. This pointer comes from userspace via sendmsg() and can be arbitrarily forged: int fd = socket(AF_ATMSVC, SOCK_DGRAM, 0); ioctl(fd, ATMSIGD_CTRL); // become ATM signaling daemon struct msghdr msg = { .msg_iov = &iov, ... }; *(unsigned long *)(buf + 4) = 0xdeadbeef; // fake vcc pointer sendmsg(fd, &msg, 0); // kernel dereferences 0xdeadbeef In normal operation, the kernel sends the vcc pointer to the signaling daemon via sigd_enq() when processing operations like connect(), bind(), or listen(). The daemon is expected to return the same pointer when responding. However, a malicious daemon can send arbitrary pointer values. Fix this by introducing find_get_vcc() which validates the pointer by searching through vcc_hash (similar to how sigd_close() iterates over all VCCs), and acquires a reference via sock_hold() if found. Since struct atm_vcc embeds struct sock as its first member, they share the same lifetime. Therefore using sock_hold/sock_put is sufficient to keep the vcc alive while it is being used. Note that there may be a race with sigd_close() which could mark the vcc with various flags (e.g., ATM_VF_RELEASED) after find_get_vcc() returns. However, sock_hold() guarantees the memory remains valid, so this race only affects the logical state, not memory safety. [1]: https://gist.github.com/mrpre/1ba5949c45529c511152e2f4c755b0f3

Source: BSIBSI_CSAFUBUNTU_USNDEBIAN_DSADEBIAN_DSASIEMENS_ADVISORYSIEMENS_ADVISORYUBUNTU_USNUBUNTU_USNUBUNTU_USNUBUNTU_USNUBUNTU_USNUBUNTU_USNUBUNTU_USNUBUNTU_USNUBUNTU_USNUBUNTU_USNUBUNTU_USNUBUNTU_USNUBUNTU_USNUBUNTU_USNUBUNTU_USNUBUNTU_USNUBUNTU_USNUBUNTU_USNUBUNTU_USNUBUNTU_USNUBUNTU_USNUBUNTU_USNUBUNTU_USNBSIBSI_CSAFCVELISTV5EUVDNVDCVEORG

Metrics

Severity
medium
Priority score
238.92
KEV status
—
Exploit maturity
no public PoC known
XIEM Effective CVSS
5.5
Source: nvd-v3
CVSS v3
5.5
CVSS v4
—
EPSS percentile
3.0 %
Low — this CVE sits in the lower 10% of all CVEs scored today.
EPSS score
0.1 %
Low — model estimates < 1% exploitation likelihood.
Published
2026-07-02 15:56 UTC
CWE
—

Reanalysis & status changes

Chronological NVD audit events for this CVE — reanalyses, CVSS updates, CPE diffs.

  1. CVE Translated2026-07-25 10:10 UTC· nvd@nist.gov
    • Translation: Title: Linux, Description: En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta: net: atm: corrige un fallo debido a un puntero vcc no validado en sigd_send() Reproductor disponible en [1]. La ruta de envío de ATM (sendmsg -> vcc_sendmsg -> sigd_send) lee el puntero vcc de msg -> vcc y lo usa directamente sin ninguna validación. Este puntero proviene del espacio de usuario a través de sendmsg() y puede ser forjado arbitrariamente: int fd = socket(AF_ATMSVC, SOCK_DGRAM, 0); ioctl(fd, ATMSIGD_CTRL); // se convierte en demonio de señalización ATM struct msghdr msg = { .msg_iov = &iov, ... }; *(unsigned long *)(buf + 4) = 0xdeadbeef; // puntero vcc falso sendmsg(fd, &msg, 0); // el kernel desreferencia 0xdeadbeef En operación normal, el kernel envía el puntero vcc al demonio de señalización a través de sigd_enq() al procesar operaciones como connect(), bind() o listen(). Se espera que el demonio devuelva el mismo puntero al responder. Sin embargo, un demonio malicioso puede enviar valores de puntero arbitrarios. Esto se soluciona introduciendo find_get_vcc() que valida el puntero buscando en vcc_hash (similar a cómo sigd_close() itera sobre todos los VCC), y adquiere una referencia a través de sock_hold() si se encuentra. Dado que struct atm_vcc incrusta struct sock como su primer miembro, comparten la misma vida útil. Por lo tanto, usar sock_hold/sock_put es suficiente para mantener el vcc activo mientras se está utilizando. Tenga en cuenta que puede haber una condición de carrera con sigd_close() que podría marcar el vcc con varias banderas (por ejemplo, ATM_VF_RELEASED) después de que find_get_vcc() retorne. Sin embargo, sock_hold() garantiza que la memoria permanece válida, por lo que esta condición de carrera solo afecta el estado lógico, no la seguridad de la memoria. [1]: https://gist.github.com/mrpre/1ba5949c45529c511152e2f4c755b0f3

Affected operating systems

  • linux

    amazon / amazon_linux

  • linux

    ubuntu / awsbionic

  • linux

    ubuntu / awsjammy

  • linux

    ubuntu / awsnoble

  • linux

    ubuntu / awsresolute

  • linux

    ubuntu / awsxenial

  • linux

    ubuntu / aws-6.8jammy

  • linux

    ubuntu / aws-hwexenial

  • linux

    ubuntu / azurejammy

  • linux

    ubuntu / azurenoble

  • linux

    ubuntu / azureresolute

  • linux

    ubuntu / azurexenial

  • linux

    ubuntu / azure-4.15bionic

  • linux

    suse / basesystem_module15

  • linux

    debian / debian_linux11.0

  • linux

    debian / debian_linux12.0

  • linux

    debian / debian_linux13.0

  • linux

    suse / development_tools_module15

  • linux

    redhat / enterprise_linux9.0

  • linux

    redhat / enterprise_linux10.0

  • linux

    redhat / enterprise_linux8.0

  • linux

    redhat / enterprise_linux_aus8.6

  • linux

    redhat / enterprise_linux_aus8.4

  • linux

    redhat / enterprise_linux_eus9.6

Affected products

Products and version ranges extracted from the vendor/CERT advisory. A range like „<4.14.6“ implies the update recommendation „upgrade to 4.14.6 or later“.

  • arista

    cloudvision_agni2024.4.0 – 2025.2.2

  • arista

    cloudvision_portal2024.2.0 – 2026.1.0

  • arista

    velocloud_edge4.5.0 – 6.4.1

  • arista

    velocloud_gateway

  • arista

    velocloud_orchestrator

  • IBM

    QRadar SIEM<7.5.0 UP15 IF06

  • redhat

    openshift_container_platform4.12 – 4.12.89

  • redhat

    openshift_container_platform4.13 – 4.13.66

  • redhat

    openshift_container_platform4.14 – 4.14.65

  • redhat

    openshift_container_platform4.15 – 4.15.64

  • redhat

    openshift_container_platform4.16 – 4.16.61

  • redhat

    openshift_container_platform4.17 – 4.17.53

  • redhat

    openshift_container_platform4.18 – 4.18.40

  • redhat

    openshift_container_platform4.19 – 4.19.30

  • redhat

    openshift_container_platform4.20 – 4.20.21

  • redhat

    openshift_container_platform4.21 – 4.21.14

  • redhat

    openshift_container_platform

  • siemens

    simatic_ax_runtime

  • suse

    caas_platform

  • suse

    enterprise_storage

  • suse

    manager_proxy

  • suse

    manager_retail_branch_server

  • suse

    manager_server

  • suse

    openstack_cloud

References & sources

Linked CVEs

Show 491 more CVEs
IDCVE-2026-31411
Linux kernel (Xilinx) vulnerabilities — CVE-2026-31411 | NEOSEC Intel