CVE-2026-53078 Linux CVE debrief

Who should care

Linux kernel users and administrators should be aware of this vulnerability, as it can be exploited to gain unauthorized access to sensitive information. Affected systems include those using the Linux kernel with BPF sock_ops programs. Users should ensure their systems are updated with the latest kernel patches to mitigate this vulnerability.

Technical summary

The vulnerability is caused by the SOCK_OPS_GET_SK() and SOCK_OPS_GET_FIELD() macros failing to zero the destination register when dst_reg == src_reg. This can lead to stack-out-of-bounds access and kernel pointer leaks. The fix involves changing JMP_A(1) to JMP_A(2) in the fullsock path and adding BPF_MOV64_IMM(si->dst_reg, 0) after the temp register restore in the !fullsock path. The vulnerability has a CVSS score of 7.8 and is considered high-severity.

Defensive priority

High priority should be given to patching affected Linux kernel systems, as this vulnerability can be exploited to gain unauthorized access to sensitive information. Administrators should ensure their systems are updated with the latest kernel patches to mitigate this vulnerability.

Recommended defensive actions

• Patch Linux kernel systems with the latest kernel patches
• Ensure BPF sock_ops programs are updated to use the fixed SOCK_OPS_GET_SK() and SOCK_OPS_GET_FIELD() macros
• Monitor systems for suspicious activity related to BPF sock_ops programs
• Perform regular vulnerability scans and risk assessments
• Implement compensating controls, such as additional monitoring and logging

Evidence notes

The vulnerability was discovered in the Linux kernel and has been resolved by the Linux kernel community. The fix involves changing JMP_A(1) to JMP_A(2) in the fullsock path and adding BPF_MOV64_IMM(si->dst_reg, 0) after the temp register restore in the !fullsock path. The vulnerability has a CVSS score of 7.8 and is considered high-severity.

Official resources