CVE-2026-57434
Nokogiri: Null Pointer Dereference calling methods on uninitialized wrapper classes
Nokogiri is an open source XML and HTML library for the Ruby programming language. Prior to 1.19.4, Nokogiri contains a bug when calling certain methods on allocated-but-uninitialized native wrapper classes that inherit from Nokogiri::XML::Node. This caused a NULL pointer dereference that could crash the process. This vulnerability is fixed in 1.19.4.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- Low
Exploit likelihood
What each source reports
CVE List Score used
1.7
Nokogiri: Null Pointer Dereference calling methods on uninitialized wrapper classes
Nokogiri is an open source XML and HTML library for the Ruby programming language. Prior to 1.19.4, Nokogiri contains a bug when calling certain methods on allocated-but-uninitialized native wrapper classes that inherit from Nokogiri::XML::Node. This caused a NULL pointer dereference that could crash the process. This vulnerability is fixed in 1.19.4.
- Record
CVE-2026-57434- CVSS 4.0
- 1.7 Low
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 - Weakness
- CWE-476
- Updated
- 2026-11-02
EUVDEUVD-2026-39424
1.7
Nokogiri is an open source XML and HTML library for the Ruby programming language. Prior to 1.19.4, Nokogiri contains a bug when calling certain methods on allocated-but-uninitialized native wrapper classes that inherit from Nokogiri::XML::Node. This caused a NULL pointer dereference that could crash the process. This vulnerability is fixed in 1.19.4.
- Record
EUVD-2026-39424- CVSS 4.0
- 1.7 Low
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 - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-9cv2-cfxc-v4v2
1.7
Nokogiri: Null Pointer Dereference calling methods on uninitialized wrapper classes
Summary
Nokogiri contains a bug when calling certain methods on allocated-but-uninitialized native wrapper classes that inherit from Nokogiri::XML::Node. This caused a NULL pointer dereference that could crash the process.
Nokogiri 1.19.4 checks for missing native data pointers and raises a RuntimeError.
JRuby is not affected.
Severity
The Nokogiri maintainers have evaluated this as low severity. This is only triggered by a programming error. It requires application code to call .allocate directly on a native-backed class and then invoke methods on the resulting uninitialized object. It cannot be triggered by untrusted input or through normal use of the public API.
Mitigation
Upgrade to Nokogiri 1.19.4 or later.
Avoid calling .allocate directly on Nokogiri native-backed classes. Use the documented constructors and factory methods instead.
Credit
This issue was responsibly reported by Zheng Yu from depthfirst.com.
- Record
GHSA-9cv2-cfxc-v4v2- CVSS 4.0
- 1.7 Low
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 - Weakness
- CWE-476
- Updated
- 2026-11-02
NVD
1.7
Nokogiri is an open source XML and HTML library for the Ruby programming language. Prior to 1.19.4, Nokogiri contains a bug when calling certain methods on allocated-but-uninitialized native wrapper classes that inherit from Nokogiri::XML::Node. This caused a NULL pointer dereference that could crash the process. This vulnerability is fixed in 1.19.4.
- Record
CVE-2026-57434- CVSS 4.0
- 1.7 Low
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/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-476
- Updated
- 2026-11-02
OSVBELL-CVE-2026-57434
7.5
- Record
BELL-CVE-2026-57434- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSV
1.7
Nokogiri: Null Pointer Dereference calling methods on uninitialized wrapper classes
Nokogiri is an open source XML and HTML library for the Ruby programming language. Prior to 1.19.4, Nokogiri contains a bug when calling certain methods on allocated-but-uninitialized native wrapper classes that inherit from Nokogiri::XML::Node. This caused a NULL pointer dereference that could crash the process. This vulnerability is fixed in 1.19.4.
- Record
CVE-2026-57434- CVSS 4.0
- 1.7 Low
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 - Weakness
- CWE-476
- Updated
- 2026-11-02
Show 4 moreShow less
OSVDEBIAN-CVE-2026-57434
7.5
Nokogiri is an open source XML and HTML library for the Ruby programming language. Prior to 1.19.4, Nokogiri contains a bug when calling certain methods on allocated-but-uninitialized native wrapper classes that inherit from Nokogiri::XML::Node. This caused a NULL pointer dereference that could crash the process. This vulnerability is fixed in 1.19.4.
- Record
DEBIAN-CVE-2026-57434- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVGHSA-9cv2-cfxc-v4v2
1.7
Nokogiri: Null Pointer Dereference calling methods on uninitialized wrapper classes
Summary
Nokogiri contains a bug when calling certain methods on allocated-but-uninitialized native wrapper classes that inherit from Nokogiri::XML::Node. This caused a NULL pointer dereference that could crash the process.
Nokogiri 1.19.4 checks for missing native data pointers and raises a RuntimeError.
JRuby is not affected.
Severity
The Nokogiri maintainers have evaluated this as low severity. This is only triggered by a programming error. It requires application code to call .allocate directly on a native-backed class and then invoke methods on the resulting uninitialized object. It cannot be triggered by untrusted input or through normal use of the public API.
Mitigation
Upgrade to Nokogiri 1.19.4 or later.
Avoid calling .allocate directly on Nokogiri native-backed classes. Use the documented constructors and factory methods instead.
Credit
This issue was responsibly reported by Zheng Yu from depthfirst.com.
- Record
GHSA-9cv2-cfxc-v4v2- CVSS 4.0
- 1.7 Low
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 - Weakness
- CWE-476
- Updated
- 2026-11-02
OSVUBUNTU-CVE-2026-57434
1.7
Nokogiri is an open source XML and HTML library for the Ruby programming language. Prior to 1.19.4, Nokogiri contains a bug when calling certain methods on allocated-but-uninitialized native wrapper classes that inherit from Nokogiri::XML::Node. This caused a NULL pointer dereference that could crash the process. This vulnerability is fixed in 1.19.4.
- Record
UBUNTU-CVE-2026-57434- CVSS 4.0
- 1.7 Low
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 - CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVAZL-91074 No score
CVE-2026-57434 affecting package rubygem-nokogiri for versions less than 1.19.4-1
Nokogiri is an open source XML and HTML library for the Ruby programming language. Prior to 1.19.4, Nokogiri contains a bug when calling certain methods on allocated-but-uninitialized native wrapper classes that inherit from Nokogiri::XML::Node. This caused a NULL pointer dereference that could crash the process. This vulnerability is fixed in 1.19.4.
- Record
AZL-91074- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
nokogiriRubyGems |
before 1.19.4 | 1.19.4 |
rubygem-nokogiriAzure Linux:3 |
before 1.19.4-1 | 1.19.4-1 |
ruby-nokogiriAlpaquita:stream |
1.13.9-r1 up to 1.19.4-r0 | 1.19.4-r0 |
ruby-nokogiriDebian:12 |
All versions, plus listed versions 1.13.10+dfsg-21.14.2+dfsg-11.14.3+dfsg-11.14.3+dfsg-21.15.4+dfsg-1 Show 12 moreShow less1.16.0+dfsg-11.16.0+dfsg-21.16.2+dfsg-11.16.4+dfsg-11.17.2+dfsg-1~exp11.18.10+dfsg-11.18.10+dfsg-21.18.10+dfsg-31.18.2+dfsg-11.19.1+dfsg-11.19.3+dfsg-11.19.4+dfsg-1 |
None known |
ruby-nokogiriDebian:13 |
All versions, plus listed versions 1.18.10+dfsg-11.18.10+dfsg-21.18.10+dfsg-31.18.2+dfsg-11.19.1+dfsg-11.19.3+dfsg-11.19.4+dfsg-1 |
None known |
ruby-nokogiriDebian:14 |
before 1.19.4+dfsg-1, plus listed versions 1.18.10+dfsg-11.18.10+dfsg-21.18.10+dfsg-31.18.2+dfsg-11.19.1+dfsg-11.19.3+dfsg-1 |
1.19.4+dfsg-1 |
nokogiriRubyGems |
before 1.19.4, plus listed versions 1.0.01.0.11.0.21.0.31.0.4 Show 45 moreShow less1.0.51.0.61.0.71.1.01.1.11.10.01.10.0.rc11.10.11.10.101.10.21.10.31.10.41.10.51.10.61.10.71.10.81.10.91.11.01.11.0.rc11.11.0.rc21.11.0.rc31.11.0.rc41.11.11.11.21.11.31.11.41.11.51.11.61.11.71.12.01.12.0.rc11.12.11.12.21.12.31.12.41.12.51.13.01.13.11.13.101.13.21.13.31.13.41.13.51.13.61.13.7 |
1.19.4 |
ruby-nokogiriUbuntu:Pro:14.04:LTS |
All versions, plus listed versions 1.5.9-21.5.9-31.6.0-11.6.1+ds-11.6.1+ds-1ubuntu0.1~esm1 |
None known |
ruby-nokogiriUbuntu:16.04:LTS |
All versions, plus listed versions 1.6.6.2+ds-2build21.6.6.3-11.6.7-11.6.7.1-11.6.7.2-31.6.7.2-3build11.6.7.2-3ubuntu0.1 |
None known |
ruby-nokogiriUbuntu:18.04:LTS |
All versions, plus listed versions 1.8.0-11.8.1-11.8.1-1build11.8.2-1build11.8.2-1ubuntu0.1 |
None known |
Show 6 moreShow less
| Package | Affected | Fixed |
|---|---|---|
ruby-nokogiriUbuntu:Pro:20.04:LTS |
All versions, plus listed versions 1.10.3+dfsg1-21.10.4+dfsg1-11.10.7+dfsg1-11.10.7+dfsg1-21.10.7+dfsg1-2build11.10.7+dfsg1-2ubuntu0.1~esm2 |
None known |
ruby-nokogiriUbuntu:Pro:22.04:LTS |
All versions, plus listed versions 1.11.1+dfsg-2ubuntu11.11.7+dfsg-31.11.7+dfsg-3build11.13.1+dfsg-21.13.1+dfsg-2ubuntu0.1~esm1 |
None known |
ruby-nokogiriUbuntu:24.04:LTS |
All versions, plus listed versions 1.14.3+dfsg-21.16.2+dfsg-11.16.2+dfsg-1build1 |
None known |
ruby-nokogiriUbuntu:25.10 |
All versions, plus listed versions 1.16.4+dfsg-1build11.18.2+dfsg-1build1 |
None known |
ruby-nokogiriUbuntu:26.10 |
All versions, plus listed versions 1.18.10+dfsg-31.19.1+dfsg-11.19.3+dfsg-11.19.4+dfsg-1 |
None known |
ruby-nokogiriUbuntu:26.04:LTS |
All versions, plus listed versions 1.18.2+dfsg-1build11.18.10+dfsg-21.18.10+dfsg-3 |
None known |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-57434 is a low vulnerability (CVSS 1.7) in Nokogiri, published June 19, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.46%, the 40th percentile. Fixed in nokogiri 1.19.4.
References
github.com/sparklemotion/nokogiri/security/advisories/GHSA-9cv2-cfxc-v4v2
github.com/advisories/GHSA-9cv2-cfxc-v4v2
nvd.nist.gov/vuln/detail/CVE-2026-57434
docs.bell-sw.com/security/cves/CVE-2026-57434
github.com/CVEProject/cvelistV5/tree/main/cves/2026/57xxx/CVE-2026-57434.json
security-tracker.debian.org/tracker/CVE-2026-57434
github.com/sparklemotion/nokogiri
ubuntu.com/security/CVE-2026-57434
cve.org/CVERecord?id=CVE-2026-57434
Left out here: 144 versions. The JSON record has them.