# CVE-2019-15903: Memory corruption in n/a

> Crafted XML input causes a heap-based buffer over-read in libexpat, potentially leading to denial of service or information disclosure.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/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:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 4 Sep 2019
- **Updated:** 14 Oct 2026
- **Also known as:** ALPINE-CVE-2019-15903, CLEANSTART-2026-BU09886, DEBIAN-CVE-2019-15903, DLA-1912-1, DSA-4530-1, GHSA-w829-6hpw-frjf, JLSEC-2025-41, MGASA-2019-0321, SUSE-SU-2019:2429-1, SUSE-SU-2019:2440-1, UBUNTU-CVE-2019-15903, USN-4132-1, USN-4132-2, openSUSE-SU-2019:2204-1, openSUSE-SU-2019:2205-1

## What is CVE-2019-15903?

CVE-2019-15903 is a medium-severity memory corruption vulnerability in Libexpat Project Libexpat, published on 4 Sep 2019. 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

In libexpat before 2.2.8, crafted XML input could fool the parser into changing from DTD parsing to document parsing too early; a consecutive call to XML_GetCurrentLineNumber (or XML_GetCurrentColumnNumber) then resulted in a heap-based buffer over-read.

Weakness: CWE-776 (Improper Restriction of Recursive Entity References in DTDs), CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2019-15903?

It affects 2 products.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `expat` | SUSE:Linux Enterprise Desktop 12 SP4 | All versions | 2.1.0-21.9.1 |
| `expat` | SUSE:Linux Enterprise Module for Basesystem 15 | All versions | 2.2.5-3.6.1 |
| `expat` | SUSE:Linux Enterprise Module for Basesystem 15 SP1 | All versions | 2.2.5-3.6.1 |
| `expat` | SUSE:Linux Enterprise Server 12 SP4 | All versions | 2.1.0-21.9.1 |
| `expat` | SUSE:Linux Enterprise Server for SAP Applications 12 SP4 | All versions | 2.1.0-21.9.1 |
| `expat` | SUSE:Linux Enterprise Software Development Kit 12 SP4 | All versions | 2.1.0-21.9.1 |
| `expat` | openSUSE:Leap 15.0 | All versions | 2.2.5-lp150.2.6.1 |
| `expat` | openSUSE:Leap 15.1 | All versions | 2.2.5-lp151.3.6.1 |

Products: Libexpat Project Libexpat, Python Python.

## How do I fix CVE-2019-15903?

Upgrade to a fixed version.

## Is CVE-2019-15903 being exploited?

There is no known exploitation of CVE-2019-15903 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-2019-15903 and fix it if it is affected.

What it is: CVE-2019-15903 is a medium-severity memory corruption vulnerability in Libexpat Project Libexpat, published on 4 Sep 2019. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2019-15903 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-2019-15903/ (Markdown: https://insights.sbomify.com/CVE-2019-15903/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2019-15903
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-15903
- OSV: https://osv.dev/vulnerability/CVE-2019-15903

---
From sbomify Insights: https://insights.sbomify.com/CVE-2019-15903/
Summaries are generated and may contain mistakes; the official description above is the record.