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.
CVE-2026-79770
HIGHPre-NVD 7.57.5—Trending — 3 sources updated this week
EchelonGraph scoreHIGH confidence
Score 7.5 from GitHub Security Advisory (severity: HIGH) published 2026-08-25. a secondary CVSS source baseline 7.5; sources differ by 0.0.
Triggered by: GitHub Security Advisory CVSS
Sources: ghsa, secondary
7.5EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
- High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: —CVSS: 7.5Exploit: None knownExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 7.5
- EG Score
- 7.5(high)
- EG Risk
- 38(Track)EG Risk 38/100SSVC: Track
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity75% × 45%Exploitation0% × 40%Automatability30% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- —
- EPSS %ILE
- —
- KEV
- Not listed
Published
August 25, 2026
Last Modified
August 25, 2026
Advisory Details (1)
Auto-updated Aug 25, 2026Patch available. Sources: github.
github Patch Available
Regular expression backtracking in Nokogiri CSS selector tokenizer · Advisory · sparklemotion/nokogiri · GitHub
https://github.com/sparklemotion/nokogiri/security/advisories/GHSA-c4rq-3m3g-8wgxVendor Advisories for CVE-2026-79770(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 5× in last 7d / 5× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-08-26 05:40 UTCEG score recompute
- 2026-08-26 05:40 UTCGHSA enrichment
- 2026-08-25 16:24 UTCEG score recompute
- 2026-08-25 15:30 UTCEG score recompute
- 2026-08-25 15:29 UTCMITRE cvelistV5first tracked
Frequently asked(4)
What is CVE-2026-79770?
CVE-2026-79770 is a high vulnerability published on August 25, 2026. 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…
When was CVE-2026-79770 disclosed?
CVE-2026-79770 was first published in the National Vulnerability Database on August 25, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
What is the CVSS score of CVE-2026-79770?
CVE-2026-79770 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2026-79770?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-79770, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-79770
Is Your Infrastructure Affected by CVE-2026-79770?
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