CVE-2026-87929

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 ImpacttotalSuccessful exploitation gives total 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

0.52% probability of exploitation activity in the next 30 days.

EPSS percentile

Equal to or higher than the score of 44.3% of scored records. A rank, not a probability.

NVD base score

9.3 (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:H/VI:H/VA:H/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 2026-09-14.

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

2026-09-09 16:45Z1 MO AGO

Last updated

2026-09-24 14:21Z1 MO AGO

Reserved

2026-09-09

Assigning CNA

VulnCheck

Record state

PUBLISHED

Severity

Critical (CVSS 9.3)

CNA CVSS vector

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

Weaknesses

• CWE-321Use of Hard-coded Cryptographic KeyVariant

Data version

5.2

Document digest

67b571ba58b5017c6d144dd1b1f22b5826845988eaa263c0929132e513a99d42

• github.comhttps://github.com/maxsite/cmsproduct
• github.comhttps://github.com/EviL0rd/maxsite-cve4/blob/main/2026.09.08-maxsite-cms-hardcoded-session-key-auth-bypass.mdexploittechnical-description
• github.comhttps://github.com/maxsite/cms/blob/2ca0a0c7d1d71106a25dbb0f2aedaaefbf12802c/application/config/config.php#L230-L254technical-description
• github.comhttps://github.com/maxsite/cms/blob/2ca0a0c7d1d71106a25dbb0f2aedaaefbf12802c/application/maxsite/common/core/init.php#L70-L96technical-description
• www.vulncheck.comVulnCheck Advisory: MaxSite CMS through 109.6 Authentication Bypass via Hardcoded Encryption Keyhttps://www.vulncheck.com/advisories/maxsite-cms-through-109.6-authentication-bypass-via-hardcoded-encryption-keythird-party-advisory