CVE-2026-98626
Received
Received - Intake
BPF CO-RE Relocation Validation Bypass
Vulnerability report for CVE-2026-98626, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.
Publication date: 2026-10-18
Last updated on: 2026-10-18
Assigner: kernel.org
Description
Description
In the Linux kernel, the following vulnerability has been resolved:
bpf: Restrict CO-RE poisoning to relocatable instructions
CO-RE relocation records can name any instruction offset. When a
relocation cannot be resolved, bpf_core_patch_insn() currently poisons its
target before checking whether that instruction is a valid relocation
target. Malformed metadata can therefore replace jumps, calls, exits,
register-source arithmetic, or non-immediate loads instead of failing at
the relocation step.
Handle poisoning only after the instruction has passed the same class and
operand-form checks used for a resolved relocation. Route invalid forms
through the existing diagnostic and return a hard error. Keep poisoning
supported instructions, including both halves of a plain ldimm64, so an
unresolved relocation in dead code remains valid.
Extend bpf_core_poison_insn() to poison both halves of ldimm64, and return
its status directly from each validated instruction case. This avoids
routing the success path through a common label and leaves the helper free
to report errors.
The shared relocation code applies this restriction to both libbpf and
in-kernel CO-RE.
CVSS Scores
EPSS Scores
| Probability: | |
| Percentile: |
Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| Linux | Linux | d7a252708dbc950ca2064310217e8b9f85846e2f |
| Linux | Linux | d7a252708dbc950ca2064310217e8b9f85846e2f |
| Linux | Linux | d7a252708dbc950ca2064310217e8b9f85846e2f |
| Linux | Linux | d7a252708dbc950ca2064310217e8b9f85846e2f |
| Linux | Linux | d7a252708dbc950ca2064310217e8b9f85846e2f |
| Linux | Linux | d7a252708dbc950ca2064310217e8b9f85846e2f |
| Linux | Linux | d7a252708dbc950ca2064310217e8b9f85846e2f |
| Linux | Linux | 5.6 |
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-UNKNOWN |
