Vulnerability in Nokogiri
CVE-2026-79771
Nokogiri versions before 1.19.3 contain a memory leak in the XSLT Stylesheet transform method when processing Ruby strings containing null bytes. Attackers can exploit this by passing attacker-controlled input with null bytes to transform parameters, causing heap allocations to leak and enabling denial of service against long-running processes.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.
EPSS exploit prediction
EPSS: 0.004 (34.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 35th percentile — 34.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.004 · change: +0.001
Affected products
Weakness classification (CWE)
References
- github.com/sparklemotion/nokogiri/security/advisories/GHSA-v2fc-qm4h-8hqv (vendor-advisory, Vendor Advisory)
- www.vulncheck.com/advisories/nokogiri-before-memory-leak-via-xslt-transform (Third Party Advisory, third-party-advisory)
Frequently asked questions
- What is CVE-2026-79771?
- CVE-2026-79771 is a medium-severity vulnerability in Nokogiri, classified under Missing Release of Memory after Effective Lifetime. CVSS score: 5.3/10. Published 2026-08-25.
- How severe is CVE-2026-79771?
- Medium severity. CVSS v3 base score is 5.3 out of 10.