Is CVE-2026-4509 in the CISA KEV catalog?

No. CVE-2026-4509 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2026-4509?

CVE-2026-4509 has a CVSS v3 base score of 6.3 (MEDIUM).

What is the EPSS score for CVE-2026-4509?

CVE-2026-4509 has an EPSS score of 0.29% (21th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix or mitigate CVE-2026-4509?

No published fix for CVE-2026-4509 has been found yet. Check the linked vendor advisories for guidance as it becomes available.

CVE & CISA-KEV Catalog

CVE-2026-4509

MEDIUM

6.3

CVSS v3

NVD

Description

A security flaw has been discovered in PbootCMS up to 3.2.12. This affects an unknown function of the file core/function/file.php of the component File Upload. The manipulation of the argument black results in incomplete blacklist. The attack may be launched remotely. The exploit has been released to the public and may be used for attacks.

CWE-183 CWE-184

How to fix

No published remediation has been found for this vulnerability's affected products yet.

Mitigation guidance may be in the linked vendor advisories in the References section below.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredLow

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityLow

IntegrityLow

AvailabilityLow

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L

Exploit Intelligence

0.29%probability of exploitation in 30 days

21stpercentile

Low risk: more likely to be exploited than 21% of all known CVEs.

References

Other references4

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-04-29.