# CVE-2026-64313: crypto: ecc - Fix carry overflow in vli multiplication

> An integer overflow in Linux kernel ECC multiplication causes incorrect cryptographic results, potentially compromising data integrity or security.

- **Severity:** High 8.8 (`CVSS:3.1/AV:A/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:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 25 Jul 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-93653, BELL-CVE-2026-64313, DEBIAN-CVE-2026-64313, GHSA-x49g-5fpg-2qxf, ROOT-OS-DEBIAN-12-CVE-2026-64313, ROOT-OS-UBUNTU-2204-CVE-2026-64313, UBUNTU-CVE-2026-64313

## What is CVE-2026-64313?

CVE-2026-64313 is a high-severity vulnerability in Linux kernel, published on 25 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:

crypto: ecc - Fix carry overflow in vli multiplication

The carry flag calculation fails when r01.m_high is saturated
(0xFFFFFFFFFFFFFFFF) and addition of lower bits overflows.

The condition (r01.m_high < product.m_high) doesn't handle the case
where r01.m_high == product.m_high and an additional carry exists
from lower-bit overflow.

When commit 3c4b23901a0c ("crypto: ecdh - Add ECDH software support")
introduced crypto/ecc.c, it split the muladd() function in the
micro-ecc library into separate mul_64_64() and add_128_128() helpers.
It seems the check got lost in translation.

Add proper handling for this boundary by accounting for the carry
from the lower addition.

Weakness: CWE-190 (Integer Overflow or Wraparound)

## Which versions are affected by CVE-2026-64313?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-64313?

Apply the vendor's patch.

## Is CVE-2026-64313 being exploited?

There is no known exploitation of CVE-2026-64313 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-2026-64313 and fix it if it is affected.

What it is: CVE-2026-64313 is a high-severity vulnerability in Linux kernel, published on 25 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-2026-64313 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-2026-64313/ (Markdown: https://insights.sbomify.com/CVE-2026-64313/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-64313
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-64313
- OSV: https://osv.dev/vulnerability/CVE-2026-64313

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-64313/
Summaries are generated and may contain mistakes; the official description above is the record.