# CVE-2025-39998: scsi: target: target_core_configfs: Add length check to avoid buffer overflow

> A buffer overflow in the Linux kernel SCSI target subsystem allows attackers to cause a crash or potentially execute code via crafted input.

- **Severity:** High 7.1 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/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:** 15 Oct 2025
- **Updated:** 15 Oct 2026
- **Also known as:** AZL-68504, BELL-CVE-2025-39998, DEBIAN-CVE-2025-39998, GHSA-h5vm-jvgf-qf7m, ROOT-OS-DEBIAN-11-CVE-2025-39998, ROOT-OS-DEBIAN-12-CVE-2025-39998, ROOT-OS-DEBIAN-13-CVE-2025-39998, ROOT-OS-UBUNTU-2204-CVE-2025-39998, ROOT-OS-UBUNTU-2404-CVE-2025-39998, UBUNTU-CVE-2025-39998

## What is CVE-2025-39998?

CVE-2025-39998 is a high-severity memory corruption vulnerability in Linux, published on 15 Oct 2025. 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:

scsi: target: target_core_configfs: Add length check to avoid buffer overflow

A buffer overflow arises from the usage of snprintf to write into the
buffer "buf" in target_lu_gp_members_show function located in
/drivers/target/target_core_configfs.c. This buffer is allocated with
size LU_GROUP_NAME_BUF (256 bytes).

snprintf(...) formats multiple strings into buf with the HBA name
(hba->hba_group.cg_item), a slash character, a devicename (dev->
dev_group.cg_item) and a newline character, the total formatted string
length may exceed the buffer size of 256 bytes.

Since snprintf() returns the total number of bytes that would have been
written (the length of %s/%sn ), this value may exceed the buffer length
(256 bytes) passed to memcpy(), this will ultimately cause function
memcpy reporting a buffer overflow error.

An additional check of the return value of snprintf() can avoid this
buffer overflow.

## Which versions are affected by CVE-2025-39998?


## How do I fix CVE-2025-39998?

Apply the vendor's patch.

## Is CVE-2025-39998 being exploited?

There is no known exploitation of CVE-2025-39998 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-39998 and fix it if it is affected.

What it is: CVE-2025-39998 is a high-severity memory corruption vulnerability in Linux, published on 15 Oct 2025. 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-2025-39998 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-2025-39998/ (Markdown: https://insights.sbomify.com/CVE-2025-39998/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-39998
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-39998
- OSV: https://osv.dev/vulnerability/CVE-2025-39998

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-39998/
Summaries are generated and may contain mistakes; the official description above is the record.