CVE-2021-47996
Nokogiri's bundled libxml2 has memory corruption flaws causing DoS and data leaks.
Is CVE-2021-47996 being exploited?
Not confirmed. CVE-2021-47996 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. EPSS currently estimates a 0.50% probability of exploitation in the next 30 days.
How severe is CVE-2021-47996?
CVE-2021-47996 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-2021-47996?
Yes. A fix has been recorded for CVE-2021-47996. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2021-47996 affect?
CVE-2021-47996 affects Nokogiri (CRuby) < 1.11.4 with vendored libxml2 2.9.10, Ruby applications parsing untrusted XML using vendored libxml2 2.9.10, Any app bundling libxml2 2.9.10. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2021-47996?
Upgrade Nokogiri to >=1.11.4 or libxml2 to >=2.9.12 immediately.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Processing crafted XML can cause denial of service, information disclosure, or memory corruption potentially enabling code execution.
Patch when possible