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Fencer Vulns
medium 4.8

CVE-2021-3111 json

The Express Entries Dashboard in Concrete5 8.5.4 allows stored XSS via the name field of a new data object at an index.php/dashboard/expres…

published 2021-01-08 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-26463

cvss
4.8
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
3.0%
EPSS 3.0% chance of exploitation in 30 days, percentile 87%
public exploits
1
Exploit-DB

Summary

The Express Entries Dashboard in Concrete5 8.5.4 allows stored XSS via the name field of a new data object at an index.php/dashboard/express/entries/view/ URI.

Patch / fix

  • concretecms concrete_cms 8.5.5

Timeline

  1. Published
  2. First public exploit (EDB-49721)

Exploit prediction

3.04% chance of exploitation in the next 30 days, higher than 87% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • EDB-49721 Concrete5 8.5.4 - 'name' Stored XSS webapps, 2021-03-29
  • github.com https://github.com/Quadron-Research-Lab/CVE/blob/main/CVE-2021-3111.pdf referenced PoC, tagged "exploit" by a source, unverified
  • packetstormsecurity.com http://packetstormsecurity.com/files/161600/Concrete5-8.5.4-Cross-Site-Scripting.html referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 4.8 CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N
NVD 2.0 3.5 AV:N/AC:M/Au:S/C:N/I:P/A:N

Classification

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

References

Sources

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.