Vulnerability · Published Jun 25, 2026 · Assigned by GitHub_M
CVE-2026-57436Nokogiri: Possible Use-After-Free when setting `Document#root=` to an invalid node type
Low 1.7
In plain English
A low-severity use-after-free in nokogiri from sparklemotion. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 35% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
Nokogiri is an open source XML and HTML library for the Ruby programming language. Prior to 1.19.4, Nokogiri::XML::Document#root= validated only that the new root was a Nokogiri::XML::Node, allowing a DTD node to be set as the document root. The result is a heap use-after-free during garbage collection or finalization, leading to an invalid memory read or potentially a segfault. This vulnerability is fixed in 1.19.4.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | ruby-nokogiri | no fix listed | DEBIAN-CVE-2026-57436 |
| Debian:13 | ruby-nokogiri | no fix listed | DEBIAN-CVE-2026-57436 |
| Debian:14 | ruby-nokogiri | 1.19.4+dfsg-1 | DEBIAN-CVE-2026-57436 |
| RubyGems | nokogiri | 1.19.4 | GHSA-wjv4-x9w8-wm3h |
| Ubuntu:24.04:LTS | ruby-nokogiri | no fix listed | UBUNTU-CVE-2026-57436 |
| Ubuntu:25.10 | ruby-nokogiri | no fix listed | UBUNTU-CVE-2026-57436 |
| Ubuntu:26.04:LTS | ruby-nokogiri | no fix listed | UBUNTU-CVE-2026-57436 |
| Ubuntu:26.10 | ruby-nokogiri | no fix listed | UBUNTU-CVE-2026-57436 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| sparklemotion | nokogiri | < 1.19.4 |
Weakness: CWE-416 · Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U