CVE-2025-71346
Heap under-read in libxml2 via Nokogiri when validating certain XML schemas
Is CVE-2025-71346 being exploited?
Not confirmed. CVE-2025-71346 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-2025-71346?
CVE-2025-71346 is rated High. 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-2025-71346?
Yes. A fix has been recorded for CVE-2025-71346. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2025-71346 affect?
CVE-2025-71346 affects Nokogiri < 1.18.8, libxml2 < 2.13.8, Ruby apps using Nokogiri that validate XML schemas. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2025-71346?
Upgrade Nokogiri to >=1.18.8 and libxml2 to >=2.13.8; avoid validating untrusted schemas.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Memory corruption from XML Schema validation of untrusted schemas/docs — may cause crashes or potential data disclosure.
Patch when possible