CVE-2026-57236
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.
Does this matter?
Lower severity and a low EPSS score (0.34%). Track it; it rarely justifies an emergency change on its own.
Description
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.
- CVSS 4.0
- 1.7 LOWCVSS: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/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
- EPSS
- 0.34% probability · 27th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-416
- Affected
- nokogiri/nokogiri
- Source
- security-advisories@github.com
References
- https://github.com/sparklemotion/nokogiri/security/advisories/GHSA-5v8h-3h3q-446pMitigation, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.