FluentCMS PermissionManager.cs GetAccessible authorization

published 2026-09-07 2 mo ago modified 2026-09-09 1 mo ago also EUVD-2026-72253

cvss: 4.7; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.4%; EPSS 0.4% chance of exploitation in 30 days, percentile 34%
public exploits: 0; none known

A vulnerability was found in FluentCMS up to 0.0.5. This affects the function GetAccessible of the file src/Backend/FluentCMS.Services/Permissions/PermissionManager.cs. Performing a manipulation results in missing authorization. It is possible to initiate the attack remotely. The exploit has been made public and could be used. The project was informed of the problem early through an issue report but has not responded yet.

CISA SSVC

Exploitation: Proof of concept is public
Automatable: no
Technical impact: partial
Assessed: 1 mo ago (2026-09-09)

Exploit prediction

0.40% chance of exploitation in the next 30 days, higher than 34% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

github.com https://github.com/fluentcms/FluentCMS/issues/2409 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	4.0	5.1	CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P
CNA	3.1	4.7	CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:L/E:P/RL:X/RC:R
CNA	3.0	4.7	CVSS:3.0/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:L/E:P/RL:X/RC:R
CNA	2.0	5.8	AV:N/AC:L/Au:M/C:P/I:P/A:P/E:POC/RL:ND/RC:UR
CNA	4.0	2.0	CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P/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
CNA	3.1	4.7	CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:L
CNA	2.0	5.8	AV:N/AC:L/Au:M/C:P/I:P/A:P

Affected products

n/a FluentCMS

Classification

Weakness

CWE-862 Missing Authorization
CWE-863 Incorrect Authorization

References

github.com /fluentcms/FluentCMS/issues/2409
exploit, issue-tracking
vuldb.com /vuln/399430
vdb-entry, technical-description
vuldb.com /vuln/399430/cti
signature, permissions-required
vuldb.com /cve/CVE-2026-86271
third-party-advisory
vuldb.com /submit/904824
third-party-advisory
github.com /fluentcms/FluentCMS/
product

Sources

CVE List CVE-2026-86271
NVD CVE-2026-86271

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary