CVE-2026-4420

CVE-2026-4420 is a medium-severity vulnerability in Bludit with a CVSS 3.x base score of 5.4. 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-79.

Key facts

Description

Bludit is vulnerable to Stored Cross-Site Scripting (XSS) in its page creating functionality. An authenticated attacker with page creation privileges (such as Author, Editor, or Administrator) can embed a malicious JavaScript payload in the tags field of a newly created article. This payload will be executed when a victim visits the URL of the uploaded resource. The uploaded resource itself is accessible without authentication. Critically, this vulnerability could be used to automatically create a new site administrator if the victim has enough privileges.  The vendor was notified early about this vulnerability, but didn't respond with the details of vulnerability or vulnerable version range. Only versions 3.17.2 and 3.18.0 were tested and confirmed as vulnerable, other versions were not tested and might also be vulnerable.

Frequently asked questions

What is CVE-2026-4420?
Bludit is vulnerable to Stored Cross-Site Scripting (XSS) in its page creating functionality. An authenticated attacker with page creation privileges (such as Author, Editor, or Administrator) can embed a malicious JavaScript payload in the tags field of a newly created article. This payload will be executed when a victim visits the URL of the uploaded resource. The uploaded resource itself is accessible without authentication. Critically, this vulnerability could be used to automatically create a new site administrator if the victim has enough privileges.  The vendor was notified early about this vulnerability, but didn't respond with the details of vulnerability or vulnerable version range. Only versions 3.17.2 and 3.18.0 were tested and confirmed as vulnerable, other versions were not tested and might also be vulnerable.
How severe is CVE-2026-4420?
CVE-2026-4420 has a CVSS 3.x base score of 5.4, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2026-4420 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (6th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-4420?
CVE-2026-4420 primarily affects Bludit. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2026-4420?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-4420 have an EU (EUVD) identifier?
Yes. CVE-2026-4420 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-19598.
When was CVE-2026-4420 published?
CVE-2026-4420 was published on 2026-04-07 and last updated on 2026-06-17.

References

Affected products (2)

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