SB2026081510 - NULL pointer dereference in Linux kernel rxrpc

Description

This security bulletin contains information about 1 vulnerability.

1) NULL pointer dereference (CVE-ID: CVE-2026-74430)

CWE-ID: CWE-476 - NULL Pointer Dereference

CVSSv4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to a null pointer dereference in rxrpc_input_ackall() when processing forged ACKALL packets for a new service call before any reply packets have been queued. A remote attacker can send a forged ACKALL packet to cause a denial of service.

The issue can be triggered when the call is in RXRPC_CALL_SERVER_RECV_REQUEST state and the transmit queue has not been initialized.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/523cb585672ae681b2d3b0d620aec5313774e2e2
• https://git.kernel.org/stable/c/8db6a2c95e36938076b37466ce36774526a5c8c3
• https://git.kernel.org/stable/c/9b6ce594808580b2a19e6e1aa459ef56c0153ac1