# CVE-2023-52426: Denial of service in n/a

> Attackers can cause denial of service via recursive XML entity expansion in libexpat when XML_DTD is undefined at compile time.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/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:** 4 Feb 2024
- **Updated:** 15 Oct 2026
- **Also known as:** ALPINE-CVE-2023-52426, AZL-34208, AZL-34684, BELL-CVE-2023-52426, CLEANSTART-2026-CM07098, DEBIAN-CVE-2023-52426, ECHO-3235-462b-0d89, GHSA-mp2w-hjcj-f5g9, JLSEC-2025-59, UBUNTU-CVE-2023-52426

## What is CVE-2023-52426?

CVE-2023-52426 is a medium-severity denial of service vulnerability in Libexpat Project Libexpat, published on 4 Feb 2024. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

libexpat through 2.5.0 allows recursive XML Entity Expansion if XML_DTD is undefined at compile time.

Weakness: CWE-776 (Improper Restriction of Recursive Entity References in DTDs)

## Which versions are affected by CVE-2023-52426?

It affects 1 product.


Products: Libexpat Project Libexpat.

## How do I fix CVE-2023-52426?

Upgrade to a fixed version.

## Is CVE-2023-52426 being exploited?

There is no known exploitation of CVE-2023-52426 in the wild and no public exploit code.

## Other vulnerabilities in Libexpat Project Libexpat

- [CVE-2024-45490](https://insights.sbomify.com/CVE-2024-45490/): Integer overflow in n/a (critical 9.8)
- [CVE-2026-66046](https://insights.sbomify.com/CVE-2026-66046/): Expat Denial of Service via storeAtts() Quadratic Complexity (high 8.7)
- [CVE-2021-46143](https://insights.sbomify.com/CVE-2021-46143/): Integer overflow in n/a (high 8.1)
- [CVE-2017-11742](https://insights.sbomify.com/CVE-2017-11742/): Privilege escalation in n/a (high 7.8)
- [CVE-2025-59375](https://insights.sbomify.com/CVE-2025-59375/): Denial of service in libexpat (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-52426 and fix it if it is affected.

What it is: CVE-2023-52426 is a medium-severity denial of service vulnerability in Libexpat Project Libexpat, published on 4 Feb 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-2023-52426 in the wild and no public exploit code.

Affected product: Libexpat Project Libexpat. 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-2023-52426/ (Markdown: https://insights.sbomify.com/CVE-2023-52426/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-52426
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-52426
- OSV: https://osv.dev/vulnerability/CVE-2023-52426

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-52426/
Summaries are generated and may contain mistakes; the official description above is the record.