CVE-2026-43633
CRITICAL: Unauthenticated root RCE in HestiaCP web terminal (v1.9.0–1.9.4).
Is CVE-2026-43633 being exploited?
Not confirmed. CVE-2026-43633 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 1.1% probability of exploitation in the next 30 days.
How severe is CVE-2026-43633?
CVE-2026-43633 is rated Critical with a CVSS score of 9.5. 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-2026-43633?
Not known from our data. No patch reference has been recorded for CVE-2026-43633, 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-2026-43633 affect?
CVE-2026-43633 affects HestiaCP 1.9.0-1.9.4, HestiaCP Web Terminal feature. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-43633?
Upgrade to patched version or vendor guidance; disable web terminal if not required.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Unauthenticated remote root code execution via deserialized web terminal session data in HTTP headers.
Patch when possible
- affected>= 1.9.0 and <= 1.9.4
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.