CVE-2026-53090: In the Linux kernel, the following vulnerability has been resolved: bpf: Fix ld_{abs,ind} failure path analysis in subprogs Usage of ld_{abs,ind} in...

Description

In the Linux kernel, the following vulnerability has been resolved: bpf: Fix ld_{abs,ind} failure path analysis in subprogs Usage of ld_{abs,ind} instructions got extended into subprogs some time ago via commit 09b28d76eac4 ("bpf: Add abnormal return checks."). These are only allowed in subprograms when the latter are BTF annotated and have scalar return types. The code generator in bpf_gen_ld_abs() has an abnormal exit path (r0=0 + exit) from legacy cBPF times. While the enforcement is on scalar return types, the verifier must also simulate the path of abnormal exit if the packet data load via ld_{abs,ind} failed. This is currently not the case. Fix it by having the verifier simulate both success and failure paths, and extend it in similar ways as we do for tail calls. The success path (r0=unknown, continue to next insn) is pushed onto stack for later validation and the r0=0 and return to the caller is done on the fall-through side.

Metrics

EPSS Probability

0.15%

5.0th percentile

Probability of exploitation in the next 30 days. Learn more

References

Timeline

Published: Jun 24, 2026
Last Modified: Jun 24, 2026
Status: Received

Frequently Asked Questions

What is CVE-2026-53090?

In the Linux kernel, the following vulnerability has been resolved: bpf: Fix ld_{abs,ind} failure path analysis in subprogs Usage of ld_{abs,ind} instructions got extended into subprogs some time ago via commit 09b28d76eac4 ("bpf: Add abnormal return checks."). These are only allowed in subprograms when the latter are BTF annotated and have scalar return types. The code generator in bpf_gen_ld_abs() has an abnormal exit path (r0=0 + exit) from legacy cBPF times. While the enforcement is on scalar return types, the verifier must also simulate the path of abnormal exit if the packet data load via ld_{abs,ind} failed. This is currently not the case. Fix it by having the verifier simulate both success and failure paths, and extend it in similar ways as we do for tail calls. The success path (r0=unknown, continue to next insn) is pushed onto stack for later validation and the r0=0 and return to the caller is done on the fall-through side.

How severe is CVE-2026-53090?

Severity scoring for CVE-2026-53090 is pending analysis. The EPSS model estimates a 0.15% probability of exploitation in the next 30 days.

How do I fix CVE-2026-53090?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.