# CVE-2025-4948: Libsoup: integer underflow in soup_multipart_new_from_message() leading to denial of service in libsoup

> An integer underflow in libsoup allows attackers to crash applications via crafted multipart messages, causing denial of service.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 19 May 2025
- **Updated:** 30 Jun 2026
- **Also known as:** AZL-61921, AZL-61953, DEBIAN-CVE-2025-4948, GHSA-5c6q-hvvg-576r, ROOT-OS-DEBIAN-12-CVE-2025-4948, UBUNTU-CVE-2025-4948

## What is CVE-2025-4948?

CVE-2025-4948 is a high-severity vulnerability in Red Hat Enterprise Linux 10, published on 19 May 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A flaw was found in the soup_multipart_new_from_message() function of the libsoup HTTP library, which is commonly used by GNOME and other applications to handle web communications. The issue occurs when the library processes specially crafted multipart messages. Due to improper validation, an internal calculation can go wrong, leading to an integer underflow. This can cause the program to access invalid memory and crash. As a result, any application or server using libsoup could be forced to exit unexpectedly, creating a denial-of-service (DoS) risk.

Weakness: CWE-191 (Integer Underflow (Wrap or Wraparound))

## Which versions are affected by CVE-2025-4948?


## How do I fix CVE-2025-4948?

Apply the vendor's patch.

## Is CVE-2025-4948 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-4948 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-4948 and fix it if it is affected.

What it is: CVE-2025-4948 is a high-severity vulnerability in Red Hat Enterprise Linux 10, published on 19 May 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-4948 exists.

Affected product: Red Hat Enterprise Linux 10. 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-2025-4948/ (Markdown: https://insights.sbomify.com/CVE-2025-4948/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-4948
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-4948
- OSV: https://osv.dev/vulnerability/CVE-2025-4948

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-4948/
Summaries are generated and may contain mistakes; the official description above is the record.