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MEDIUM severity

CVE-2013-6461 — nokogiri

MEDIUM

CVE-2013-6461 is a medium-severity (CVSS 6.5) CWE-776 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 vulnerable to DoS while parsing XML entities

Published
Updated
Affected
2 pkgs
Patched
2 / 2
Exploits
1 known
Exploitation data as of Nov 3, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗
2.2%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs82th percentile — riskier than 82% of all scored CVEsHighest risk
1.55%1.93%2.31%2.69%2.0%2.2%May 26Sep 26Nov 26

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

2 pkgs affected
💎nokogiri💎nokogiri

Real-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

Nokogiri gem 1.5.x and 1.6.x has DoS while parsing XML entities by failing to apply limits

Affected Packages

2 total 2 fixed
EcosystemPackageVulnerable rangeFix
💎RubyGemsnokogiri≥ 1.5.0&&< 1.5.111.5.11bundle update nokogiri --conservative
💎RubyGemsnokogiri≥ 1.6.0&&< 1.6.11.6.1bundle update nokogiri --conservative

Affected Products

7 products · 11 configurations
OS
debian linuxdebian
3 versions
8.09.010.0
Application
nokogirinokogiri
≥ 1.6.0 && < 1.6.1
range
Application
cloudforms management engineredhat
1 version
5.0
OS
enterprise mrgredhat
1 version
2.0
Application
openstackredhat
2 versions
3.04.0
Application
satelliteredhat
1 version
6.0
Exploits & PoCs
1

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

Nokogiri gem 1.5.x and 1.6.x has DoS while parsing XML entities by faili…

bugzilla.redhat.comNVDJul 2021

Detection & mitigation playbook

Open-source dependency

  1. Detect

    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.

  2. Fix

    Update nokogiri to 1.5.11 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2013-6461 is resolved across your whole dependency graph.

  3. Workarounds

    Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.

Frequently Asked Questions

Nokogiri gem 1.5.x and 1.6.x has DoS while parsing XML entities by failing to apply limits
O3 Security · Impact-Aware SCA

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Find it across RubyGems, including transitive dependencies.

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CVE-2013-6461: nokogiri DoS — Fixed in 1.5.11