How severe is CVE-2026-4509?

CVE-2026-4509 has a CVSS 3.x base score of 6.3, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability low.

Is CVE-2026-4509 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (21st percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-4509?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-4509 have an EU (EUVD) identifier?

Yes. CVE-2026-4509 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-14239.

When was CVE-2026-4509 published?

CVE-2026-4509 was published on 2026-03-21 and last updated on 2026-06-17.

CVE-2026-4509

CVE-2026-4509 is a medium-severity vulnerability with a CVSS 3.x base score of 6.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-183.

Key facts

Severity: Medium (CVSS 3.x base score 6.3)
CVSS v2: 6.5
CVSS v4: 2.1
EPSS exploit prediction: 0% (21st percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-14239
Weakness: CWE-183
Published: 2026-03-21
Last modified: 2026-06-17

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.

Frequently asked questions

What is CVE-2026-4509?: 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.
How severe is CVE-2026-4509?: CVE-2026-4509 has a CVSS 3.x base score of 6.3, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability low.
Is CVE-2026-4509 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (21st percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-4509?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-4509 have an EU (EUVD) identifier?: Yes. CVE-2026-4509 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-14239.
When was CVE-2026-4509 published?: CVE-2026-4509 was published on 2026-03-21 and last updated on 2026-06-17.

References

Other CWE-183 vulnerabilities

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