CVE-2026-57236CWE-416

Nokogiri: Possible Use-After-Free when `Nokogiri::XML::Document#encoding=` raises an exception

Low · published June 25, 2026

CVSS v4.0
1.7
EPSS
0%
Percentile
35.9
In the wild
Unconfirmed
What it is

Nokogiri is an open source XML and HTML library for the Ruby programming language. Prior to 1.19.4, calling Document#encoding= with an invalid encoding (e.g., a non-string, or a string containing a null byte) raises an exception, but only after freeing the document's current encoding string without replacing it. The document is left referencing freed memory, so the next call to Document#encoding reads invalid memory, which can cause a segfault or leak freed bytes into a Ruby String. Affects the CRuby (libxml2) implementation only; JRuby is not affected. This vulnerability is fixed in 1.19.4.

The record
Technical detail
CVSS v4.0
1.7 · LOW
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
EPSS
0.00426 · 35.9th percentile
Weakness
CWE-416 · Use After Free
Published
2026-06-25T14:29Z
EPSS history
Timeline
  • 25 JUN 14:29Z
    Nokogiri: Possible Use-After-Free when `Nokogiri::XML::Document#encoding=` raises an exception
    cvelistv5