CVE-2026-53090 bpf: Fix ld_{abs,ind} failure path analysis in subprogs
The Linux kernel BPF verifier failed to simulate abnormal exit paths for packet load instructions in subprograms, potentially leading to incorrect program validation.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-53090?
CVE-2026-53090 is a high-severity vulnerability in Linux kernel, published on 24 Jun 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official 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.
Weakness: CWE-253
Which versions are affected by CVE-2026-53090?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-53090?
Apply the vendor's patch.
Is CVE-2026-53090 being exploited?
There is no known exploitation of CVE-2026-53090 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-90374, BELL-CVE-2026-53090, DEBIAN-CVE-2026-53090, GHSA-h443-hx93-m7qc, ROOT-OS-DEBIAN-11-CVE-2026-53090, ROOT-OS-DEBIAN-12-CVE-2026-53090 and 4 more.