An issue was discovered in Orckestra C1 CMS through 6.6.

published 2019-12-23 6 y ago modified 2026-06-17 4 mo ago also EUVD-2019-8011

cvss: 8.8; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 2.6%; EPSS 2.6% chance of exploitation in 30 days, percentile 85%
public exploits: 0; none known

An issue was discovered in Orckestra C1 CMS through 6.6. The EntityTokenSerializer class in Composite.dll is prone to unvalidated deserialization of wrapped BinaryFormatter payloads, leading to arbitrary remote code execution for any low-privilege user.

Patch / fix

links 1

github.com/Orckestra/C1-CMS-Foundation/commits/dev patch

Exploit prediction

2.56% chance of exploitation in the next 30 days, higher than 85% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
NVD	3.1	8.8	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
NVD	2.0	6.5	AV:N/AC:L/Au:S/C:P/I:P/A:P

Classification

Weakness

CWE-502 Deserialization of Untrusted Data

References

github.com /Orckestra/C1-CMS-Foundation/commits/dev
patch

Sources

CVE List CVE-2019-18211
NVD CVE-2019-18211

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.

Summary