CVE-2025-71406
Use-after-free in Nokogiri's bundled libxslt allowing memory corruption via crafted XSLT.
Is CVE-2025-71406 being exploited?
Not confirmed. CVE-2025-71406 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked.
How severe is CVE-2025-71406?
CVE-2025-71406 is rated High with a CVSS score of 8.7. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2025-71406?
Yes. A fix has been recorded for CVE-2025-71406. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2025-71406 affect?
CVE-2025-71406 affects Nokogiri < 1.18.4, libxslt < 1.1.43, Ruby applications using Nokogiri XSLT processing. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2025-71406?
Upgrade Nokogiri to >=1.18.4 (libxslt 1.1.43); sanitize/untrust XSLT inputs; redeploy.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Processing attacker-crafted XSLT can trigger use-after-free leading to memory corruption, possible remote code execution or crash (DoS) in affected apps.
Patch when possible