Nokogiri versions before 1.19.3 contain regular expression denial of service vulnerabilities in the CSS selector tokenizer affecting string-literal and identifier tokenization. Attackers can inject adversarial CSS selectors into methods like Node#css, Node#at_css, and Searchable#search to cause exponential regex backtracking and denial of service.

Metrics

Attack Vector Network

Attack Complexity Low

Privileges Required None

Attack Requirements None

User Interaction None

Vulnerable System Confidentiality Impact None

Vulnerable System Integrity Impact None

Vulnerable System Availability Impact High

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Exploitation none

Automatable yes

Technical Impact partial

Affected Vendors & Products

Vendors Products
Nokogiri Subscribe
Nokogiri Subscribe

No data.

No data.

No data.

Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://github.com/sparklemotion/nokogiri/security/advisories/GHSA-c4rq-3m3g-8wgx cve-icon cve-icon
https://www.vulncheck.com/advisories/nokogiri-before-redos-via-css-selector-tokenizer cve-icon cve-icon
History

Tue, 25 Aug 2026 16:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Tue, 25 Aug 2026 15:30:00 +0000

Type Values Removed Values Added
Description Nokogiri versions before 1.19.3 contain regular expression denial of service vulnerabilities in the CSS selector tokenizer affecting string-literal and identifier tokenization. Attackers can inject adversarial CSS selectors into methods like Node#css, Node#at_css, and Searchable#search to cause exponential regex backtracking and denial of service.
Title Nokogiri before 1.19.3 ReDoS via CSS selector tokenizer
First Time appeared Nokogiri
Nokogiri nokogiri
Weaknesses CWE-1333
CPEs cpe:2.3:a:nokogiri:nokogiri:*:*:*:*:*:*:*:*
Vendors & Products Nokogiri
Nokogiri nokogiri
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

cvssV4_0

{'score': 8.7, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N'}

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-08-25T16:10:31.778Z

Reserved: 2026-08-25T14:29:43.528Z

Link: CVE-2026-79770

cve-icon Vulnrichment

Updated: 2026-08-25T16:10:28.512Z

cve-icon NVD

Status : Received

Published: 2026-08-25T16:17:28.460

Modified: 2026-08-25T16:17:28.460

Link: CVE-2026-79770

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses