CVE-2026-64004

high

Description

In the Linux kernel, the following vulnerability has been resolved: net/iucv: fix locking in .getsockopt Mirror iucv_sock_setsockopt() and wrap the whole switch in lock_sock()/release_sock(). The pre-existing SO_MSGLIMIT-only lock becomes redundant and is removed. Any AF_IUCV HIPER user can potentially crash the kernel by racing recvmsg() with getsockopt(SO_MSGSIZE): the SO_MSGSIZE arm dereferences iucv->hs_dev->mtu after iucv_sock_close() (called from the racing recvmsg()) has set hs_dev to NULL, producing a NULL pointer dereference oops.

References

https://git.kernel.org/stable/c/cd691beafea0dd779e69e81ccc26b0ab50efcb5e

https://git.kernel.org/stable/c/9817369243380e287ebe5525411557eaa3aa2a79

https://git.kernel.org/stable/c/884eb247b74d86db97e3a37f0d6fc8e1e83590dd

https://git.kernel.org/stable/c/6e792b8dd3002bbc4136745928a9605df1a72b8a

https://git.kernel.org/stable/c/69554adc7a6fa04ede3ad7512321d83748e3c920

https://git.kernel.org/stable/c/45bb8de8c95d8899f4b8f61bd9bceb8132af73cb

https://git.kernel.org/stable/c/3589d20a666caf30ad100c960a2de7de390fce88

https://git.kernel.org/stable/c/1fc30bd4e55e2dd622d2d366cecd732c1841bbee

Details

Source: Mitre, NVD

Published: 2026-07-19

Updated: 2026-07-20

Risk Information

CVSS v2

Base Score: 6.8

Vector: CVSS2#AV:L/AC:L/Au:S/C:C/I:C/A:C

Severity: Medium

CVSS v3

Base Score: 7.8

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Severity: High

EPSS

EPSS: 0.00176