# CVE-2025-70101: Memory corruption in n/a

> Attackers can cause denial of service in applications using lwext4 by providing a crafted ext4 image, triggering an out-of-bounds read.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 3 Jun 2026
- **Updated:** 29 Jun 2026
- **Also known as:** GHSA-4v99-r46p-gx3v

## What is CVE-2025-70101?

CVE-2025-70101 is a medium-severity memory corruption vulnerability in n/a, published on 3 Jun 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

An out-of-bounds read in the ext4_ext_binsearch_idx function in src/ext4_extent.c of the lwext4 1.0.0 library allows attackers to cause a denial of service by supplying a specially crafted ext4 filesystem image. The vulnerability occurs due to insufficient validation of extent header fields before performing a binary search over extent index entries, which can result in invalid pointer calculations and an out-of-bounds memory read during extent tree traversal.

Weakness: CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2025-70101?

It affects 1 product.


Products: Gkostka Lwext4.

## How do I fix CVE-2025-70101?

No fix has been published for CVE-2025-70101 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-70101 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-70101 exists.

## Other vulnerabilities in n/a

- [CVE-2025-70100](https://insights.sbomify.com/CVE-2025-70100/): Denial of service in n/a (medium 5.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-70101 and fix it if it is affected.

What it is: CVE-2025-70101 is a medium-severity memory corruption vulnerability in n/a, published on 3 Jun 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-70101 exists.

Affected product: n/a. 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-2025-70101/ (Markdown: https://insights.sbomify.com/CVE-2025-70101/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-70101
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-70101
- OSV: https://osv.dev/vulnerability/CVE-2025-70101

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-70101/
Summaries are generated and may contain mistakes; the official description above is the record.