CVE-2026-8134

highpriority · track · 29EPSS 0.007 · 54 %ileEUUS

grimoire priorityP2 · Scheduled

Exploitable?

—

no known exploitation

Likely / severe?

0.74% (54th) EPSS

CVSS 7.2 · high

Is it mine?

3 products

Check your exposure

Who says so?

4 sources

cnnvd · enisa_euvd · nvd · osv

EPSS · scored 2026-10-27

Concrete CMS 9.5.0 and below fails to sanitize path traversal sequences in the ptComposerFormLayoutSetControlCustomTemplate field when saving page type composer form layouts. An authenticated rogue administrator with composer form editing rights can exploit this to include arbitrary readable files on the server. Combined with the file uploader's extension-only validation (which permits PHP code in files saved with image extensions like .png), this can result in authenticated remote code execution. The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 9.4 with vector CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H Thanks Yonatan Drori (Tenzai) for reporting.

cvss

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

9.4

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · high–critical · 7.2–9.4

v3.17.2highCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:Hprimary · NVD / NIST USexploitability 1.2 · impact 5.9

v3.17.2highCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:Hsecondary · OSV

v4.09.4criticalCVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:Hsecondary · ENISA EU

v4.09.4criticalCVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/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

v4.07.6highCVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:U/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: no · Technical Impact: totalcoordinatorcisa_ssvcUS

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-23USCWE-23USCWE-434USCWE-98US

affected products (3)

Products and version ranges known to be affected.

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

advisories (1)

Vendor and ecosystem advisories describing this.

GHSA-645j-cm4x-3xvwConcrete CMS Vulnerable to Relative Path Traversal2026-05-21ghsa · osvUS
Concrete CMS 9.5.0 and below fails to sanitize path traversal sequences in the ptComposerFormLayoutSetControlCustomTemplate field when saving page type composer form layouts. An authenticated rogue administrator with composer form editing rights can exploit this to include arbitrary readable files on the server. Combined with the file uploader's extension-only validation (which permits PHP code in files saved with image extensions like .png), this can result in authenticated remote code execution. Concrete CMS thanks Yonatan Drori (Tenzai) for reporting this issue.

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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