# CVE-2024-39480: kdb: Fix buffer overflow during tab-complete

> A buffer overflow in the Linux kernel kdb debugger allows attackers to execute arbitrary code or escalate privileges via tab completion.

- **Severity:** High 8.4 (`CVSS:3.1/AV:L/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:** 5 Jul 2024
- **Updated:** 5 Aug 2026
- **Also known as:** AZL-43294, BELL-CVE-2024-39480, DEBIAN-CVE-2024-39480, GHSA-32jg-6c46-hc8j, UBUNTU-CVE-2024-39480

## What is CVE-2024-39480?

CVE-2024-39480 is a high-severity memory corruption vulnerability in Linux kernel, published on 5 Jul 2024. 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:

kdb: Fix buffer overflow during tab-complete

Currently, when the user attempts symbol completion with the Tab key, kdb
will use strncpy() to insert the completed symbol into the command buffer.
Unfortunately it passes the size of the source buffer rather than the
destination to strncpy() with predictably horrible results. Most obviously
if the command buffer is already full but cp, the cursor position, is in
the middle of the buffer, then we will write past the end of the supplied
buffer.

Fix this by replacing the dubious strncpy() calls with memmove()/memcpy()
calls plus explicit boundary checks to make sure we have enough space
before we start moving characters around.

Weakness: CWE-120 (Buffer Copy without Checking Size of Input), CWE-121 (Stack-based Buffer Overflow)

## Which versions are affected by CVE-2024-39480?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2024-39480?

Apply the vendor's patch.

## Is CVE-2024-39480 being exploited?

There is no known exploitation of CVE-2024-39480 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-2024-39480 and fix it if it is affected.

What it is: CVE-2024-39480 is a high-severity memory corruption vulnerability in Linux kernel, published on 5 Jul 2024. 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-2024-39480 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-2024-39480/ (Markdown: https://insights.sbomify.com/CVE-2024-39480/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-39480
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-39480
- OSV: https://osv.dev/vulnerability/CVE-2024-39480

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-39480/
Summaries are generated and may contain mistakes; the official description above is the record.