CVE-2026-43633: HestiaCP versions 1.9.0 through 1.9.4 contain a deserialization vulnerability in the web terminal component ca

This week

CRITICAL 10.0REMOTE

CVE-2026-43633 is a critical-severity flaw (CVSS 10.0) affecting affected software. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

HestiaCP versions 1.9.0 through 1.9.4 contain a deserialization vulnerability in the web terminal component caused by a session format mismatch between PHP and Node.js that allows unauthenticated remote attackers to achieve root-level code execution. Attackers can inject crafted data into HTTP headers that are processed by the PHP session handler but incorrectly deserialized by the Node.js web terminal component as trusted session values, resulti

Why this priority

Critical severity
CISA SSVC: public proof of concept
CISA SSVC: automatable with total technical impact
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	10.0 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	1.1% (top 35%)
CISA exploited list	No
Weakness	CWE-502
Published	2026-05-19
Last modified	2026-07-14

Publisher (CNA): VulnCheck

Last updated 2026-07-14 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Timeline

2026-05-19 14:16 UTCPublished CVE record published
2026-07-14 21:16 UTCUpdated Record last modified

Exact fixes by distribution

Fedora 46 · proftpd · FIXED · 1.3.9e-1.fc46 · FEDORA-2026-fc0d87d66e · source

sudo dnf upgrade --advisory=FEDORA-2026-fc0d87d66e

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-43633?

No fixed release is listed yet. Watch the vendor advisory and apply any mitigation shown on this page.

Is CVE-2026-43633 being exploited?

CVE-2026-43633 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-43633 affect?

CVE-2026-43633 affects affected software. Severity is critical (CVSS 10.0). HestiaCP versions 1.9.0 through 1.9.4 contain a deserialization vulnerability in the web terminal component caused by a session format mismatch between PHP and Node.js that allows unauthenticated remote attackers to achieve root-level code

How urgent is CVE-2026-43633?

Priority 62/100. Critical severity; CISA SSVC: public proof of concept; CISA SSVC: automatable with total technical impact; Remotely exploitable, no login, no user action

Software pages

Node.js vulnerabilities · PHP vulnerabilities

References

← Back to latest CVEs