CVE-2020-26247 XXE in Nokogiri

What is CVE-2020-26247?

CVE-2020-26247 is a low-severity vulnerability in Debian Debian Linux, published on 30 Dec 2020. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

Official description

Nokogiri is a Rubygem providing HTML, XML, SAX, and Reader parsers with XPath and CSS selector support. In Nokogiri before version 1.11.0.rc4 there is an XXE vulnerability. XML Schemas parsed by Nokogiri::XML::Schema are trusted by default, allowing external resources to be accessed over the network, potentially enabling XXE or SSRF attacks. This behavior is counter to the security policy followed by Nokogiri maintainers, which is to treat all input as untrusted by default whenever possible. This is fixed in Nokogiri version 1.11.0.rc4.

Weakness: CWE-611

Which versions are affected by CVE-2020-26247?

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

Products include Debian Debian Linux, Nokogiri Nokogiri.

How do I fix CVE-2020-26247?

Upgrade nokogiri to 1.11.0 or later.

Is CVE-2020-26247 being exploited?

There is no known exploitation of CVE-2020-26247 in the wild and no public exploit code.

Other vulnerabilities in Debian Debian Linux

• CVE-2015-3306 ProFTPD Improper Access Control Exploited Critical 10.0
• CVE-2025-49113 RoundCube Webmail Deserialization of Untrusted Data Exploited Critical 9.9
• CVE-2026-24061 GNU InetUtils Argument Injection Exploited Critical 9.8
• CVE-2025-39682 Linux Kernel Improper Check for Unusual or Exceptional Conditions Exploited Critical 9.8
• CVE-2024-9680 Mozilla Firefox Use-After-Free Exploited Critical 9.8

All Debian Debian Linux vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as DEBIAN-CVE-2020-26247, DLA-2678-1, GHSA-vr8q-g5c7-m54m, OESA-2021-1144, UBUNTU-CVE-2020-26247.