GHSA-fq42-c5rg-92c2 CVE-2022-51000

Vulnerable dependencies in Nokogiri

High RubyGems

Severity: High; The publisher's own rating, not a CVSS score
Exploit chance (EPSS): —; No score published
Known exploited: No; Not in CISA's catalog
Weakness: CWE-416 Use After Free
Fix: 1.13.2; Upgrade nokogiri to this version or later

Description

Summary

Nokogiri v1.13.2 upgrades two of its packaged dependencies:

vendored libxml2 from v2.9.12 to v2.9.13
vendored libxslt from v1.1.34 to v1.1.35

Those library versions address the following upstream CVEs:

libxslt: CVE-2021-30560 (CVSS 8.8, High severity)
libxml2: CVE-2022-23308 (Unspecified severity, see more information below)

Those library versions also address numerous other issues including performance improvements, regression fixes, and bug fixes, as well as memory leaks and other use-after-free issues that were not assigned CVEs.

Please note that this advisory only applies to the CRuby implementation of Nokogiri < 1.13.2, and only if the packaged libraries are being used. If you've overridden defaults at installation time to use system libraries instead of packaged libraries, you should instead pay attention to your distro's libxml2 and libxslt release announcements.

Mitigation

Upgrade to Nokogiri >= 1.13.2.

Users who are unable to upgrade Nokogiri may also choose a more complicated mitigation: compile and link an older version Nokogiri against external libraries libxml2 >= 2.9.13 and libxslt >= 1.1.35, which will also address these same CVEs.

Impact

libxslt CVE-2021-30560

CVSS3 score: 8.8 (High)
Fixed by https://gitlab.gnome.org/GNOME/libxslt/-/commit/50f9c9c

All versions of libxslt prior to v1.1.35 are affected.

Applications using untrusted XSL stylesheets to transform XML are vulnerable to a denial-of-service attack and should be upgraded immediately.

libxml2 CVE-2022-23308

As of the time this security advisory was published, there is no officially published information available about this CVE's severity. The above NIST link does not yet have a published record, and the libxml2 maintainer has declined to provide a severity score.
Fixed by https://gitlab.gnome.org/GNOME/libxml2/-/commit/652dd12
Further explanation is at https://mail.gnome.org/archives/xml/2022-February/msg00015.html

The upstream commit and the explanation linked above indicate that an application may be vulnerable to a denial of service, memory disclosure, or code execution if it parses an untrusted document with parse options DTDVALID set to true, and NOENT set to false.

An analysis of these parse options:

While NOENT is off by default for Document, DocumentFragment, Reader, and Schema parsing, it is on by default for XSLT (stylesheet) parsing in Nokogiri v1.12.0 and later.
DTDVALID is an option that Nokogiri does not set for any operations, and so this CVE applies only to applications setting this option explicitly.

It seems reasonable to assume that any application explicitly setting the parse option DTDVALID when parsing untrusted documents is vulnerable and should be upgraded immediately.

Affected versions

RubyGems

Package	Vulnerable	Fixed in
nokogiri	`< 1.13.2`	`1.13.2`

How to fix

Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.

nokogiri RubyGems → `1.13.2`

bundler

bundle update nokogiri # Gemfile: gem "nokogiri", ">= 1.13.2"

Weakness

CWE-416: Use After Free

The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.

How to prevent it

Architecture and Design: Choose a language that provides automatic memory management.
Implementation: When freeing pointers, be sure to set them to NULL once they are freed. However, the utilization of multiple or complex data structures may lower the usefulness of this strategy.

References

Timeline

Feb 25, 2022 Published
Sep 8, 2026 Last updated by the source

Advisory	Severity	Why it's related
GHSA-phwj-rprq-35pp Nokogiri: Possible Use-After-Free when setting an attribute value via `Nokogiri::XML::Attr#value=` or `#content=`	High	Also affects nokogiri
GHSA-wfpw-mmfh-qq69 Nokogiri: Possible Use-After-Free in XInclude Processing	Low	Also affects nokogiri
GHSA-p67v-3w7g-wjg7 Nokogiri: Possible Use-After-Free when directly using `NokogirI::XML::XPathContext` beyond document lifetime	Medium	Also affects nokogiri
GHSA-wjv4-x9w8-wm3h Nokogiri: Possible Use-After-Free when setting `Document#root=` to an invalid node type	Medium	Also affects nokogiri
GHSA-5prr-v3j2-97mh Nokogiri: Possible Out-of-Bounds Read in `Nokogiri::XML::NodeSet#[]`	High	Also affects nokogiri
GHSA-9cv2-cfxc-v4v2 Nokogiri: Null Pointer Dereference calling methods on uninitialized wrapper classes	High	Also affects nokogiri
GHSA-8678-w3jw-xfc2 Nokogiri: XML::Schema on JRuby allows network requests when NONET is set, bypassing CVE-2020-26247	Low	Also affects nokogiri
GHSA-5v8h-3h3q-446p Nokogiri: Possible Use-After-Free when `Nokogiri::XML::Document#encoding=` raises an exception	High	Also affects nokogiri

Is this in your code?

MergeHarbor checks every repository's dependencies against this database, ranks what matters by exploitability and reachability, routes it to the owning team and opens the fix pull request.

Check your repos with MergeHarbor