# CVE-2019-13118: libxslt Type Confusion vulnerability that affects Nokogiri

> An attacker can read uninitialized stack data via a crafted xsl:number instruction in libxslt, potentially exposing sensitive memory contents.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 1 Jul 2019
- **Updated:** 28 May 2026
- **Also known as:** ALPINE-CVE-2019-13118, DEBIAN-CVE-2019-13118, GHSA-cf46-6xxh-pc75, JLSEC-2026-579, UBUNTU-CVE-2019-13118

## What is CVE-2019-13118?

CVE-2019-13118 is a medium-severity vulnerability in Apple Icloud, published on 1 Jul 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

In numbers.c in libxslt 1.1.33, a type holding grouping characters of an xsl:number instruction was too narrow and an invalid character/length combination could be passed to xsltNumberFormatDecimal, leading to a read of uninitialized stack data.

Weakness: CWE-843 (Access of Resource Using Incompatible Type)

## Which versions are affected by CVE-2019-13118?

2 open source packages ship an affected version, including nokogiri. It affects 25 products.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `nokogiri` | RubyGems | All versions | 1.10.5 |
| `nokogiri` | RubyGems | All versions | 1.10.5 |

Products: Apple Icloud, Apple Iphone Os, Apple Itunes, Apple Mac Os X, Apple Macos, Apple Tvos, Canonical Ubuntu Linux, Fedoraproject Fedora, Netapp Active Iq Unified Manager, Netapp Cloud Backup, Netapp Clustered Data Ontap, Netapp E-Series Performance Analyzer, Netapp E-Series Santricity Management Plug-Ins, Netapp E-Series Santricity Os Controller, Netapp E-Series Santricity Storage Manager, Netapp E-Series Santricity Web Services, Netapp Oncommand Insight, Netapp Oncommand Workflow Automation, Netapp Ontap Select Deploy Administration Utility, Netapp Plug-in for Symantec Netbackup and 5 more.

## How do I fix CVE-2019-13118?

Upgrade nokogiri to 1.10.5 or later.

## Is CVE-2019-13118 being exploited?

There is no known exploitation of CVE-2019-13118 in the wild and no public exploit code.

## Other vulnerabilities in Apple Icloud

- [CVE-2019-8506](https://insights.sbomify.com/CVE-2019-8506/): Apple Multiple Products Type Confusion (high 8.8, exploited in the wild)
- [CVE-2020-27932](https://insights.sbomify.com/CVE-2020-27932/): Apple Multiple Products Type Confusion (high 7.8, exploited in the wild)
- [CVE-2019-8746](https://insights.sbomify.com/CVE-2019-8746/): Memory corruption in iOS (critical 9.8)
- [CVE-2019-8749](https://insights.sbomify.com/CVE-2019-8749/): Memory corruption in iOS (critical 9.8)
- [CVE-2019-8756](https://insights.sbomify.com/CVE-2019-8756/): Memory corruption in iOS (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2019-13118 and fix it if it is affected.

What it is: CVE-2019-13118 is a medium-severity vulnerability in Apple Icloud, published on 1 Jul 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2019-13118 in the wild and no public exploit code.

Affected packages and fixed versions:
- nokogiri (RubyGems): affected all versions; fixed in 1.10.5
- nokogiri (RubyGems): affected all versions; fixed in 1.10.5

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-2019-13118/ (Markdown: https://insights.sbomify.com/CVE-2019-13118/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2019-13118
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-13118
- OSV: https://osv.dev/vulnerability/CVE-2019-13118

---
From sbomify Insights: https://insights.sbomify.com/CVE-2019-13118/
Summaries are generated and may contain mistakes; the official description above is the record.