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Fencer Intel
medium 6.1

CVE-2026-81926 json

Concrete CMS 9.4.0 through 9.5.2 is vulnerable to Cross-site scripting in the location panel duplicate-path confirmation dialog

published last mo. modified last mo. also EUVD-2026-79940

cvss
6.1
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 17%
public exploits
0
none known

Summary

Concrete CMS 9.4.0 through 9.5.2 did not escape colliding page paths before rendering them in the location panel's duplicate-path confirmation dialog. The panel's check endpoint returned the submitted path unmodified in its JSON response, and client-side JavaScript inserted each value into the dialog as raw HTML, so a crafted page path executed script in the editor's authenticated browser session. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 2.0 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N. Thanks Yonatan Drori from Tenzai for reporting.

Patch / fix

  • concretecms concrete_cms 9.5.3

Is CVE-2026-81926 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
last mo.

Exploit prediction

0.26% chance of exploitation in the next 30 days, higher than 17% of all scored CVEs (FIRST EPSS, 2026-11-11).

CVSS scores

assigned by version score vector
CNA 4.0 2.0 CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N
CNA 4.0 2.0 CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:L/VI:L/VA:L/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 3.1 6.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Affected products

  • Concrete CMS Concrete CMS

Classification

Weakness
  • CWE-79 Improper Neutralization of Input During Web Page Generation

References

Sources

Fencer Intel 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.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.