CVE-2019-5815 — nokogiri
HIGHCVE-2019-5815 is a high-severity (CVSS 7.5) Out-of-bounds Write vulnerability in nokogiri. 1 public exploit or proof-of-concept reference is indexed, so weaponization risk is real. A fix is available for nokogiri — see the affected versions and patch details below.
Nokogiri implementation of libxslt vulnerable to heap corruption
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
nokogiriReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects RubyGems packages — download data is not available via public APIs for these ecosystems.
Description
Type confusion in xsltNumberFormatGetMultipleLevel prior to libxslt 1.1.33 could allow attackers to potentially exploit heap corruption via crafted XML data.
Nokogiri prior to version 1.10.5 contains a vulnerable version of libxslt. Nokogiri version 1.10.5 upgrades the dependency to libxslt 1.1.34, which contains a patch for this issue.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 💎RubyGems | nokogiri | all versions | 1.10.5bundle update nokogiri --conservative |
Affected Products
debian linuxdebianlibxsltxmlsoftResearch use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for nokogiri, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update nokogiri to 1.10.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2019-5815 is resolved across your whole dependency graph.
Workarounds
Stop feeding it untrusted input: reject or quarantine files and payloads from unverified sources until you can upgrade, restrict accepted formats to the ones you actually need, and run the parsing or decoding step in a least-privileged sandbox or short-lived worker so a crash or corrupted read cannot reach the rest of the process.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat Enterprise Linux 6 Supplementary | chromium-browser-0:74.0.3729.108-1.el6_10 | RHSA-2019:1021 |
Frequently Asked Questions
Is CVE-2019-5815 in your dependencies?
Find it across RubyGems, including transitive dependencies.