# CVE-2026-42371: Integer overflow in uriparser

> Attackers can cause denial of service by submitting extremely large URIs, triggering numeric truncation in the uriparser library.

- **Severity:** Medium 5.1 (`CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:N/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:** 27 Apr 2026
- **Updated:** 27 Apr 2026
- **Also known as:** AZL-84396, DEBIAN-CVE-2026-42371, ECHO-3740-13e8-652e, GHSA-3f6w-rmcx-pgmh, RHSA-2026:12430, ROOT-OS-DEBIAN-12-CVE-2026-42371, UBUNTU-CVE-2026-42371

## What is CVE-2026-42371?

CVE-2026-42371 is a medium-severity vulnerability in uriparser, published on 27 Apr 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

uriparser before 1.0.1 has numeric truncation in text range comparison, if an application accepts URIs with a length in gigabytes.

Weakness: CWE-197 (Numeric Truncation Error)

## Which versions are affected by CVE-2026-42371?

It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `mingw32-uriparser` | Red Hat:hummingbird:1 | All versions | 0:1.0.1-1.hum1 |
| `mingw64-uriparser` | Red Hat:hummingbird:1 | All versions | 0:1.0.1-1.hum1 |
| `uriparser` | Red Hat:hummingbird:1 | All versions | 0:1.0.1-1.hum1 |
| `uriparser-devel` | Red Hat:hummingbird:1 | All versions | 0:1.0.1-1.hum1 |
| `uriparser-doc` | Red Hat:hummingbird:1 | All versions | 0:1.0.1-1.hum1 |

Products: Uriparser Project Uriparser.

## How do I fix CVE-2026-42371?

Upgrade to a fixed version.

## Is CVE-2026-42371 being exploited?

There is no known exploitation of CVE-2026-42371 in the wild and no public exploit code.

## Other vulnerabilities in uriparser

- [CVE-2026-44927](https://insights.sbomify.com/CVE-2026-44927/): Integer overflow in uriparser (low 2.9)
- [CVE-2026-44928](https://insights.sbomify.com/CVE-2026-44928/): Other in uriparser (low 2.9)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-42371 and fix it if it is affected.

What it is: CVE-2026-42371 is a medium-severity vulnerability in uriparser, published on 27 Apr 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-2026-42371 in the wild and no public exploit code.

Affected product: uriparser. 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-2026-42371/ (Markdown: https://insights.sbomify.com/CVE-2026-42371/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-42371
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-42371
- OSV: https://osv.dev/vulnerability/CVE-2026-42371

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-42371/
Summaries are generated and may contain mistakes; the official description above is the record.