CVE-2026-63301 — Denial of Service in Quick.CMS

In Quick.CMS, the administrative user interface restricts deletion of the primary language by omitting the corresponding option from the interface; however, the underlying language-deletion API endpoint does not enforce an equivalent server-side authorization check. As a result, an authenticated administrator can bypass the UI-level restriction and delete the primary language by sending a direct HTTP request to the API endpoint. Successful deletion of the primary language results in a Denial of Service (DoS) of application. Critically, when combined with a separate Cross-Site Request Forgery (CSRF) vulnerability (CVE-2026-1468) an unauthenticated remote attacker can craft a malicious link, which if visited by an authenticated administrator, will trigger the DoS condition without direct access to the application The vendor assessed the likelihood of exploitation as very low and…

Published Jul 28, 2026Updated Jul 28, 2026Sources: cvelistV5, CERT-PL

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the scoring sources call it.

Exploitation

Unreported

no source claims exploitation

EPSS

chance of exploitation in 30 days

Affects

opensolution

quick_cms

CVSS base

HIGH

CISA SSVC assessment

Three decision points CISA publishes for the CVEs it assesses · SSVC 2.0.3. A stakeholder decision, not a severity score.

CISA

Exploitation

None

none · proof-of-concept · active

Automatable

can an attacker script all four kill-chain steps

Technical impact

Partial

partial · total control of the vulnerable component

Affected scope

The catalog records vendors and products as separate lists, not pairs, so which product belongs to which vendor is not something this page can say.

Vendors (1)

opensolution

Products (1)

quick cms

Every base score collected

Sources score independently and disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Source
7	CVSS 4.0	HIGH	—	—	cvelistV5

Weakness & attack patterns

CWE-602

Attack patterns reported against this CVE. The ATT&CK techniques below are inferred from its weakness class.

T1134Access Token Manipulation
T1528Steal Application Access Token
T1539Steal Web Session Cookie

References

2 on the record

cert.pl/en/posts/2026/07/CVE-2026-63301
third-party-advisory
opensolution.org/
product

Elsewhere on this site

opensolutionevery CVE for this vendor
CWE-602other pages naming this weakness

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.