# CVE-2026-45870: SUNRPC: auth_gss: fix memory leaks in XDR decoding error paths

> A memory leak in the Linux kernel's SUNRPC auth_gss module allows attackers to exhaust system memory via crafted XDR decoding errors, causing denial of service.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 27 May 2026
- **Updated:** 27 May 2026
- **Also known as:** BELL-CVE-2026-45870, DEBIAN-CVE-2026-45870, GHSA-cc2x-2xg8-9rpf, ROOT-OS-UBUNTU-2204-CVE-2026-45870, ROOT-OS-UBUNTU-2404-CVE-2026-45870, UBUNTU-CVE-2026-45870

## What is CVE-2026-45870?

CVE-2026-45870 is a medium-severity denial of service vulnerability in Linux kernel, published on 27 May 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

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

SUNRPC: auth_gss: fix memory leaks in XDR decoding error paths

The gssx_dec_ctx(), gssx_dec_status(), and gssx_dec_name()
functions allocate memory via gssx_dec_buffer(), which calls
kmemdup(). When a subsequent decode operation fails, these
functions return immediately without freeing previously
allocated buffers, causing memory leaks.

The leak in gssx_dec_ctx() is particularly relevant because
the caller (gssp_accept_sec_context_upcall) initializes several
buffer length fields to non-zero values, resulting in memory
allocation:

    struct gssx_ctx rctxh = {
        .exported_context_token.len = GSSX_max_output_handle_sz,
        .mech.len = GSS_OID_MAX_LEN,
        .src_name.display_name.len = GSSX_max_princ_sz,
        .targ_name.display_name.len = GSSX_max_princ_sz
    };

If, for example, gssx_dec_name() succeeds for src_name but
fails for targ_name, the memory allocated for
exported_context_token, mech, and src_name.display_name
remains unreferenced and cannot be reclaimed.

Add error handling with goto-based cleanup to free any
previously allocated buffers before returning an error.

Weakness: CWE-401 (Missing Release of Memory after Effective Lifetime)

## Which versions are affected by CVE-2026-45870?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-45870?

Apply the vendor's patch.

## Is CVE-2026-45870 being exploited?

There is no known exploitation of CVE-2026-45870 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-45870 and fix it if it is affected.

What it is: CVE-2026-45870 is a medium-severity denial of service vulnerability in Linux kernel, published on 27 May 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-45870 in the wild and no public exploit code.

Affected product: Linux kernel. 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-2026-45870/ (Markdown: https://insights.sbomify.com/CVE-2026-45870/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-45870
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-45870
- OSV: https://osv.dev/vulnerability/CVE-2026-45870

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-45870/
Summaries are generated and may contain mistakes; the official description above is the record.