CVE-2026-52439
Critical RCE in Beetl 3.20.2 via type.new/property reflection
Is CVE-2026-52439 being exploited?
Not confirmed. CVE-2026-52439 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 0.52% probability of exploitation in the next 30 days.
How severe is CVE-2026-52439?
CVE-2026-52439 is rated Critical with a CVSS score of 9.8. 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-2026-52439?
Not known from our data. No patch reference has been recorded for CVE-2026-52439, which is not the same as no patch existing — a fix may have shipped without a tagged reference, or after this record was written. The vendor advisory is the only authority on whether a fix exists, and mitigations may be available regardless.
What does CVE-2026-52439 affect?
CVE-2026-52439 affects Beetl 3.20.2, xiandafu beetl, Applications using the Beetl template engine. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-52439?
Patch ASAP when available; disable/sandbox Beetl, restrict template input, apply WAF rules
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Remote code execution on servers running Beetl; attacker can execute arbitrary commands as the application user via template reflection.
Immediate action required