# CVE-2026-64082: riscv: Fix register corruption from uninitialized cregs on error

> An attacker can exploit uninitialized stack data in the Linux kernel to leak kernel memory or corrupt register state, potentially leading to privilege escalation.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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:** 19 Jul 2026
- **Updated:** 2 Sep 2026
- **Also known as:** AZL-92829, BELL-CVE-2026-64082, DEBIAN-CVE-2026-64082, GHSA-87cj-725f-6hr5, ROOT-OS-DEBIAN-12-CVE-2026-64082, ROOT-OS-DEBIAN-13-CVE-2026-64082, UBUNTU-CVE-2026-64082

## What is CVE-2026-64082?

CVE-2026-64082 is a high-severity vulnerability in Linux kernel, published on 19 Jul 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:

riscv: Fix register corruption from uninitialized cregs on error

compat_riscv_gpr_set() calls cregs_to_regs() unconditionally, even when
user_regset_copyin() fails. Since cregs is an uninitialized stack
variable, a copyin failure causes uninitialized stack data to be written
into the target task's pt_regs, corrupting its register state and
potentially leaking kernel stack contents.

compat_restore_sigcontext() has the same issue: it calls cregs_to_regs()
even when __copy_from_user() fails, leading to the same corruption of
the signal-returning task's register state on error.

Only call cregs_to_regs() when the user copy succeeds.

Weakness: CWE-908 (Use of Uninitialized Resource)

## Which versions are affected by CVE-2026-64082?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-64082?

Apply the vendor's patch.

## Is CVE-2026-64082 being exploited?

There is no known exploitation of CVE-2026-64082 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-2026-64082 and fix it if it is affected.

What it is: CVE-2026-64082 is a high-severity vulnerability in Linux kernel, published on 19 Jul 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-2026-64082 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-2026-64082/ (Markdown: https://insights.sbomify.com/CVE-2026-64082/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-64082
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-64082
- OSV: https://osv.dev/vulnerability/CVE-2026-64082

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-64082/
Summaries are generated and may contain mistakes; the official description above is the record.