NFSv4.1: zero referring call lists before decoding
CVE-2026-90104 · published 17 Sept 2026
How serious is it
- Severity: critical, CVSS score 9.8 out of 10.
- No exploit prediction (EPSS) score yet.
- Not on the CISA list of exploited vulnerabilities.
- No public exploit in Exploit-DB.
Is your app affected by CVE-2026-90104?
Paste this prompt into Claude Code, Cursor or any AI coding tool: it runs a free Shippable scan of your project and fixes what it finds. Built with Lovable, Bolt or v0? Scan your live app. Or upload your package file.
Who is affected
- Linux Linux: 4aece6a19cf7f474f15eb861ba74db4479884ce3 to < ed54460caf5b5aa65ec03c9a6032d831f39f19f5, 4aece6a19cf7f474f15eb861ba74db4479884ce3 to < 7510a5b9edec9d9536a4e69f10edfb2592e6cf7f, 4aece6a19cf7f474f15eb861ba74db4479884ce3 to < f4d23937e1c41995c2f54af26c89b5e48a41c299, 4aece6a19cf7f474f15eb861ba74db4479884ce3 to < f31f3c042e024aef437cda42f0424ae8d4594b6c
- Linux Linux: 2.6.31
How to check
- Find out whether you run the affected product and which version, then compare it with the versions above.
How to fix
Copies a prompt for Claude Code, Cursor or Codex that asks it to check whether you run this product.
- Apply the vendor's update or mitigation from the references below. If there is none yet, limit exposure of the affected service until there is.
- If a vulnerable version was live, check your logs and rotate the secrets that server could read.
The advisory
In the Linux kernel, the following vulnerability has been resolved:
NFSv4.1: zero referring call lists before decoding
decode_cb_sequence_args() allocates csa_rclists with kmalloc_objs(), so
each referring_call_list starts uninitialized. decode_rc_list() assigns
rcl_refcalls only when rcl_nrefcalls is nonzero. A valid list with zero
referring calls therefore leaves the pointer uninitialized, and
nfs4_callback_sequence() later passes stale slab contents to kfree().
Allocate csa_rclists with kzalloc_objs() so every rcl_refcalls member is
NULL from the beginning, including valid empty referring call lists.
Check your whole app
Dependencies are only half of it. Free and read-only: before you push, run npx shippable-dev scan localhost:3000 in your project folder, no account needed. For your live app, you prove it's yours with a one-line tag first.
References
- git.kernel.org/stable/c/ed54460caf5b5aa65ec03c9a6032d831f39f19f5
- git.kernel.org/stable/c/7510a5b9edec9d9536a4e69f10edfb2592e6cf7f
- git.kernel.org/stable/c/f4d23937e1c41995c2f54af26c89b5e48a41c299
- git.kernel.org/stable/c/f31f3c042e024aef437cda42f0424ae8d4594b6c
- git.kernel.org/stable/c/8fa4804fe62ca4155a2d8fc2789d630376cbf2fc
Merged from CVE List. Last updated 26 Oct 2026. All vulnerabilities · RSS · JSON