# CVE-2026-93207: SUNRPC: Zero rpc_gss_wire_cred at svcauth_gss_decode_credbody() entry

> A use-after-free vulnerability in the Linux kernel SUNRPC module allows attackers to exploit dangling pointers, potentially leading to code execution or system crashes.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 24 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** BELL-CVE-2026-93207, DEBIAN-CVE-2026-93207, GHSA-hcpq-g756-q7pv, UBUNTU-CVE-2026-93207

## What is CVE-2026-93207?

CVE-2026-93207 is a critical use after free vulnerability in Linux, published on 24 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

In the Linux kernel, the following vulnerability has been resolved:

SUNRPC: Zero rpc_gss_wire_cred at svcauth_gss_decode_credbody() entry

svcauth_gss_decode_credbody() writes the caller's
rpc_gss_wire_cred field by field and assigns gc_ctx.len only on
the success tail.  The caller storage is svcdata->clcred, which
lives in the per-svc_rqst gss_svc_data and is reused across
requests.  Early decode failures leave partially decoded state
mixed with residue from the prior request.

The trailing body_len tightness check is the sharpest case:
xdr_stream_decode_opaque_inline() has already written gc_ctx.data
with a borrowed inline pointer into the current request's XDR
pages, but gc_ctx.len retains its prior value.  Once the request
pages are released the pooled clcred carries a dangling pointer
paired with a stale length.

Zero the caller's rpc_gss_wire_cred at function entry so that
every early-return path leaves a deterministic all-zero cred.
On the trailing tightness-check path, gc_ctx.len is now zero
instead of stale, which neuters length-driven consumers such as
gss_svc_searchbyctx() that would otherwise walk the dangling
data pointer.

## Which versions are affected by CVE-2026-93207?


## How do I fix CVE-2026-93207?

Apply the vendor's patch.

## Is CVE-2026-93207 being exploited?

There is no known exploitation of CVE-2026-93207 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-93207 and fix it if it is affected.

What it is: CVE-2026-93207 is a critical use after free vulnerability in Linux, published on 24 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-93207 in the wild and no public exploit code.

Affected product: Linux. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-93207/ (Markdown: https://insights.sbomify.com/CVE-2026-93207/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-93207
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-93207
- OSV: https://osv.dev/vulnerability/CVE-2026-93207

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-93207/
Summaries are generated and may contain mistakes; the official description above is the record.