CVE-2026-43634

Exploitation

Public exploit code exists. CISA's assessment records a public proof of concept. That is not a report of exploitation in the wild.

SSVC decision

• ExploitationpocPublic proof-of-concept exploit code exists. Not a report of exploitation in the wild.
• AutomatableyesAn attacker can reliably automate reconnaissance through exploitation, so this scales.
• Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

0.24% probability of exploitation activity in the next 30 days.

EPSS percentile

Equal to or higher than the score of 15.0% of scored records. A rank, not a probability.

NVD base score

8.7 (CVSS v4.0), scored by the NVD independently of the CNA.

NVD CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

NVD analysis status

Deferred. NVD last modified this record on 2026-07-24.

Red Hat severity

No Red Hat rating. Red Hat rates the CVEs that affect its products.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

Published

2026-05-19 13:33Z5 MO AGO

Last updated

2026-07-14 20:01Z3 MO AGO

Reserved

2026-05-01

Assigning CNA

VulnCheck

Record state

PUBLISHED

Severity

High (CVSS 8.7)

CNA CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N

Weaknesses

• CWE-348Use of Less Trusted SourceBase

Data version

5.2

Document digest

78dff50f9731aee7906d75893af02786cd102bd70a51e653b83d6879d2e7544e

• mercuryiss.com.auhttps://mercuryiss.com.au/hestiacp-unauthenticated-rce-ip-spoofing-cve-2026-43633-cve-2026-43634technical-descriptionexploit
• github.comhttps://github.com/hestiacp/hestiacp/issues/5229issue-tracking
• github.comhttps://github.com/hestiacp/hestiacp/pull/5273issue-tracking
• github.comhttps://github.com/hestiacp/hestiacp/commit/f381e294500f671cf12716c638afd0bfde901f88patch
• www.vulncheck.comhttps://www.vulncheck.com/advisories/hestiacp-ip-spoofing-via-cf-connecting-ip-headerthird-party-advisory