How severe is CVE-2026-3347?

CVE-2026-3347 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over network with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2026-3347 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (17th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-3347?

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

Does CVE-2026-3347 have an EU (EUVD) identifier?

Yes. CVE-2026-3347 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-14175.

When was CVE-2026-3347 published?

CVE-2026-3347 was published on 2026-03-21 and last updated on 2026-06-17.

CVE-2026-3347

CVE-2026-3347 is a medium-severity vulnerability with a CVSS 3.x base score of 5.5. 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

Severity: Medium (CVSS 3.x base score 5.5)
EPSS exploit prediction: 0% (17th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-14175
Weakness: CWE-79
Published: 2026-03-21
Last modified: 2026-06-17

Description

The Multi Functional Flexi Lightbox plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the `arv_lb[message]` parameter in all versions up to, and including, 1.2 due to insufficient input sanitization and output escaping. This is due to the `arv_lb_options_val()` sanitize callback returning user input without any sanitization, and the stored `message` value being output in the `genLB()` function without escaping. This makes it possible for authenticated attackers, with Administrator-level access, to inject arbitrary web scripts in pages that will execute whenever a user accesses a page or post with the lightbox enabled.

Frequently asked questions

What is CVE-2026-3347?: The Multi Functional Flexi Lightbox plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the `arv_lb[message]` parameter in all versions up to, and including, 1.2 due to insufficient input sanitization and output escaping. This is due to the `arv_lb_options_val()` sanitize callback returning user input without any sanitization, and the stored `message` value being output in the `genLB()` function without escaping. This makes it possible for authenticated attackers, with Administrator-level access, to inject arbitrary web scripts in pages that will execute whenever a user accesses a page or post with the lightbox enabled.
How severe is CVE-2026-3347?: CVE-2026-3347 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over network with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2026-3347 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (17th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-3347?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-3347 have an EU (EUVD) identifier?: Yes. CVE-2026-3347 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-14175.
When was CVE-2026-3347 published?: CVE-2026-3347 was published on 2026-03-21 and last updated on 2026-06-17.

References

Other CWE-79 (Cross-site Scripting (XSS)) vulnerabilities

CVE-2025-49410 — Critical (CVSS 10.0): Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in Imran Emu TC…
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CVE-2024-6886 — Critical (CVSS 10.0): Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') vulnerability in Gitea…
CVE-2023-45144 — Critical (CVSS 10.0): com.xwiki.identity-oauth:identity-oauth-ui is a package to aid in building identity and service providers based on…
CVE-2023-45138 — Critical (CVSS 10.0): Change Request is an pplication allowing users to request changes on a wiki without publishing the changes directly.…
CVE-2022-4361 — Critical (CVSS 10.0): Keycloak, an open-source identity and access management solution, has a cross-site scripting (XSS) vulnerability in the…

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