CVE-2026-8337

mediumpriority · track · 31EPSS 0.003 · 24 %ileexploit · PoCEUUS

grimoire priorityP1 · Urgent

Exploitable?

Public exploit

1 exploit · PoC

Likely / severe?

0.32% (24th) EPSS

CVSS 5.3 · medium

Is it mine?

3 products

Check your exposure

Who says so?

4 sources

cnnvd · enisa_euvd · nvd · osv

EPSS · scored 2026-10-23

Concrete CMS 9.5.0 and below is vulnerable to IDOR in surveys. To be vulnerable, a site would have to be configured in such a way that both public and private surveys are present on the site. An unauthenticated attacker can vote in the restricted survey by submitting the restricted optionID through the public survey’s endpoint. The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 6.3 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N. Thanks Zer0daySec https://github.com/Zee99y for reporting

cvss

Technical severity, 0–10. One row per scoring source.

6.3

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · low–medium · 2.9–6.3

v3.15.3mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:Nprimary · NVD / NIST USexploitability 3.9 · impact 1.4

v4.06.3mediumCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:Nsecondary · ENISA EU

v4.06.3mediumCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/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:Xsecondary

v4.02.9lowCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/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:Xsecondary · CVSS-BT (t0sche)

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: none · Automatable: yes · Technical Impact: partialcoordinatorcisa_ssvcUS

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-565USCWE-565USCWE-639US

exploits (1)

Public proof-of-concept and weaponised exploit code.

aj2108/CVE-2026-8337CVE-2026-8337 is an Insecure Direct Object Reference (IDOR) vulnerability in Concrete CMS that affects the Survey feature. Unlike CVE-2026-8347 (which involved Express associations), this vulnerability allows an unauthenticated attacker to participate in a restricted/private survey under specific site configurations.PoC · poc_in_github

affected products (3)

Products and version ranges known to be affected.

Concrete CMS Concrete CMS≤ 5.0 ≤9.5.0enisa_euvdEU
concretecms concrete cms< 9.5.1nvdUScpe:2.3:a:concretecms:concrete_cms:*:*:*:*:*:*:*:*
Packagist concrete5/concrete5< 9.5.1osvUSpkg:composer/concrete5/concrete5

advisories (1)

Vendor and ecosystem advisories describing this.

GHSA-8c7c-h7px-267gConcrete CMS is vulnerable to IDOR in surveys2026-05-22ghsa · osvUS
Concrete CMS 9.5.0 and below is vulnerable to IDOR in surveys. To be vulnerable, a site would have to be configured in such a way that both public and private surveys are present on the site. An unauthenticated attacker can vote in the restricted survey by submitting the restricted optionID through the public survey’s endpoint.

also known as (3)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd nvd osv NVD CVE.org MITRE

published 2026-05-21modified 2026-07-23

references (4)

External citations — patches, advisories, analysis.

scry

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