Concrete CMS 9.5.0 and below is vulnerable to IDOR in surveys when sites are running concurrent public surveys and private surveys
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
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2026-8337
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 3 Nov 2026, 15:19 UTC · Revision 1
Source evidence
Concrete CMS 9.5.0 and below is vulnerable to IDOR in surveys when sites are running concurrent public surveys and private surveys
core-osv · Original sourcePublished 21 May 2026, 21:13 UTC
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
osv:CVE-2026-8337
Complete source record
{
"id": "7df9e5e4ae2f6fc95d96def462cb62d1c51513147ba366f91f37df08d4ec0017",
"url": "https://osv.dev/vulnerability/CVE-2026-8337",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "Concrete CMS 9.5.0 and below is vulnerable to IDOR in surveys when sites are running concurrent public surveys and private surveys",
"summary": "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",
"evidence": "osv:CVE-2026-8337",
"products": [],
"severity": "medium",
"structured": {
"id": "CVE-2026-8337",
"aliases": [
"CVE-2026-8337",
"GHSA-8c7c-h7px-267g"
],
"metrics": [
{
"type": "CVSS_V4",
"score": "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"
}
],
"affected": [
{
"ranges": [
{
"repo": "https://github.com/concretecms/concretecms",
"type": "GIT",
"events": [
{
"introduced": "0"
},
{
"fixed": "92bae566b9ec573cfb3017fcbb6db454a6586997"
}
],
"database_specific": {
"extracted_events": [
{
"range": [
{
"introduced": "5.0"
},
{
"last_affected": "9.5.0"
}
],
"source": "AFFECTED_FIELD",
"strategy": "StandardRange"
},
{
"cpe": "cpe:2.3:a:concretecms:concrete_cms:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "0"
},
{
"fixed": "9.5.1"
}
],
"source": "CPE_RANGE"
}
]
}
}
],
"versions": [
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"9.5.0RC2",
"9.5.0RC1",
"9.4.4",
"9.4.3",
"9.4.2",
"9.4.1",
"9.4.0",
"9.4.0RC2",
"9.4.0RC1",
"9.3.7",
"9.3.6",
"9.3.5",
"9.3.0",
"9.3.4",
"9.3.3",
"9.3.2",
"9.3.1",
"8.4.1",
"8.3.1",
"8.2.1",
"8.2.0",
"8.2.0RC2",
"8.1.0",
"5.7.5.7",
"5.7.5.6",
"5.7.5.5",
"5.7.5.2",
"5.7.4.1",
"5.7.3.1",
"5.7.3",
"5.7.2.1",
"5.7.2",
"5.7.0.4",
"5.7.1",
"5.7.0.3",
"5.7.0.1",
"5.7.0"
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-8337.json"
}
}
],
"modified": "2026-10-28T02:30:29.613362237Z",
"provider": "osv",
"references": [
"https://documentation.concretecms.org/9-x/developers/introduction/version-history/951-release-notes",
"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/8xxx/CVE-2026-8337.json",
"https://nvd.nist.gov/vuln/detail/CVE-2026-8337",
"https://github.com/concretecms/concretecms"
],
"provider_metadata": {
"cwe_ids": [
"CWE-565",
"CWE-639"
],
"cna_assigner": "ConcreteCMS",
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/8xxx/CVE-2026-8337.json"
}
},
"related_cves": [
{
"value": "CVE-2026-8337",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 496735,
"published_at": "2026-05-21T21:13:07.64+00:00"
}