GHSA-353f-x4gh-cqq8
Nokogiri patches vendored libxml2 to resolve multiple CVEs
- Severity
- Critical
- The publisher's own rating, not a CVSS score
- Exploit chance (EPSS)
- —
- No score published
- Known exploited
- No
- Not in CISA's catalog
- Weakness
- —
- Not classified
- Fix
1.18.9- Upgrade nokogiri to this version or later
Description
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
Affected versions
RubyGems
| Package | Vulnerable | Fixed in |
|---|---|---|
| nokogiri | < 1.18.9 |
1.18.9 |
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 → 1.18.9
- bundler
bundle update nokogiri # Gemfile: gem "nokogiri", ">= 1.18.9"
References
Advisories
Packages
Other links
Timeline
- Published
- Last updated by the source
Related advisories
| 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 |
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