Know every vulnerabilitybefore it knows you.
DevGuard continuously monitors your dependencies and alerts you when CVEs like this one affect your stack — with real-time threat intelligence built for developers.
GHSA-353f-x4gh-cqq8
No affected components available
Summary
Nokogiri v1.18.9 patches the vendored libxml2 to address CVE-2025-6021, CVE-2025-6170, CVE-2025-49794, CVE-2025-49795, and CVE-2025-49796.
Impact and severity
CVE-2025-6021
A flaw was found in libxml2's xmlBuildQName function, where integer overflows in buffer size calculations can lead to a stack-based buffer overflow. This issue can result in memory corruption or a denial of service when processing crafted input.
NVD claims a severity of 7.5 High (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)
Fixed by applying https://gitlab.gnome.org/GNOME/libxml2/-/commit/17d950ae
CVE-2025-6170
A flaw was found in the interactive shell of the xmllint command-line tool, used for parsing XML files. When a user inputs an overly long command, the program does not check the input size properly, which can cause it to crash. This issue might allow attackers to run harmful code in rare configurations without modern protections.
NVD claims a severity of 2.5 Low (CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:L)
Fixed by applying https://gitlab.gnome.org/GNOME/libxml2/-/commit/5e9ec5c1
CVE-2025-49794
A use-after-free vulnerability was found in libxml2. This issue occurs when parsing XPath elements under certain circumstances when the XML schematron has the <sch:name path="..."/> schema elements. This flaw allows a malicious actor to craft a malicious XML document used as input for libxml, resulting in the program's crash using libxml or other possible undefined behaviors.
NVD claims a severity of 9.1 Critical (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H)
Fixed by applying https://gitlab.gnome.org/GNOME/libxml2/-/commit/81cef8c5
CVE-2025-49795
A NULL pointer dereference vulnerability was found in libxml2 when processing XPath XML expressions. This flaw allows an attacker to craft a malicious XML input to libxml2, leading to a denial of service.
NVD claims a severity of 7.5 High (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)
Fixed by applying https://gitlab.gnome.org/GNOME/libxml2/-/commit/62048278
CVE-2025-49796
A vulnerability was found in libxml2. Processing certain sch:name elements from the input XML file can trigger a memory corruption issue. This flaw allows an attacker to craft a malicious XML input file that can lead libxml to crash, resulting in a denial of service or other possible undefined behavior due to sensitive data being corrupted in memory.
NVD claims a severity of 9.1 Critical (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H)
Fixed by applying https://gitlab.gnome.org/GNOME/libxml2/-/commit/81cef8c5
Affected Versions
- Nokogiri < 1.18.9 when using CRuby (MRI) with vendored libxml2
Patched Versions
- Nokogiri >= 1.18.9
Mitigation
Upgrade to Nokogiri v1.18.9 or later.
Users who are unable to upgrade Nokogiri may also choose a more complicated mitigation: compile and link Nokogiri against patched external libxml2 libraries which will also address these same issues.
References
- https://github.com/sparklemotion/nokogiri/pull/3526
- https://nvd.nist.gov/vuln/detail/CVE-2025-6021
- https://nvd.nist.gov/vuln/detail/CVE-2025-6170
- https://nvd.nist.gov/vuln/detail/CVE-2025-49794
- https://nvd.nist.gov/vuln/detail/CVE-2025-49795
- https://nvd.nist.gov/vuln/detail/CVE-2025-49796
Measures severity based on intrinsic characteristics of the vulnerability, independent of environment.
No exploitation activity has been observed at this time. Continue routine monitoring.
Probability that this vulnerability will be exploited in the wild within the next 30 days.
We did not find any exploit available. Neither in GitHub repositories nor in the Exploit-Database.
Continuously monitor your dependencies and get alerted when vulnerabilities like this one affect your stack.
Checkout DevGuard