CVE-2026-43633: hestiacp hestiacp

HestiaCP 1.9.0-1.9.4 Deserialization RCE via Web Terminal

CVSS 9.5 CriticalCriticalEPSS 0.011 · 65th percentile

Critical, because:

CVSS score 9.5: 9.0 or more.

Published by the CVE Program (CNA: VulnCheck) at 19 May 2026, 13:29 UTC. agentprime has not analysed this yet, so whether it affects any app is not known. This CVE names a vendor and product rather than a package, so the lockfile check doesn’t match it.

Affected products, as the CNA wrote them
Vendor	Product	Versions
hestiacp	hestiacp pkg:github/hestiacp/hestiacp	affected 1.9.0 to 1.9.4, inclusive semver unaffected 854d71b3c1737b0a0d0cc55c926008ffe1f6719b git Other versions: affected

Identifiers

CVE-2026-43633

CNA

VulnCheck

Weakness (CWE)

CWE-502

Not analysed yet

We haven’t published our own analysis of this CVE. If a person reviews it, this page will say what’s affected and what has to be true for it to matter.

Severity and exploitation

Score	Rating	CVSS	Vector	Source
9.5	Critical	4.0	CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H	CNA (VulnCheck)Used for this record
10.0	Critical	3.1	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H	CNA (VulnCheck)

CISA KEV Not listed.
EPSS 0.011, the 65th percentile, on 6 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

This record came from the full history of the CVE Program, published 19 May 2026. New records show when each source confirmed them.

Sources

References from the CNA

github.com/hestiacp/hestiacp/issues/5229 issue-tracking
github.com/hestiacp/hestiacp/pull/5244 issue-tracking
github.com/hestiacp/hestiacp/commit/854d71b3c1737b0a0d0cc55c926008ffe1f6719b patch
www.vulncheck.com/advisories/hestiacp-deserialization-rce-via-web-terminal third-party-advisory
mercuryiss.com.au/hestiacp-unauthenticated-rce-ip-spoofing-cve-2026-43633-cve-2026-43634 technical-descriptionexploit

Facts on this page come from the CVE List as the CNA published them, with CVSS from the sources named above, CISA KEV and FIRST EPSS. Vendors, products and versions are shown as the CNA wrote them. We don’t reproduce the CVE’s description.