Quick.CMS deserializes user-controlled data received over plaintext HTTP without ensuring integrity or authenticity. This allows attackers to tamper with serialized payloads in transit and inject malicious objects. Because deserialization is performed without proper validation or class restrictions, crafted payloads can trigger dangerous magic methods (e.g., __wakeup() and __destruct()) and leverage gadget chains, resulting in arbitrary code execution. Exploitation is triggered automatically when an administrator accesses the admin panel.
When successfully exploited, this vulnerability allows attackers to execute arbitrary code on the server via manipulated serialized data transmitted over an unprotected channel.
This issue was mitigated by limiting the communication to HTTPS in a patch for version 6.8 published on 14.05.2026, deployments without this patch remain vulnerable.
SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Track* at high (mission-essential systems).
No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines, and watch the vendor's advisory for the fix.
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table
BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.
In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it