CVE-2026-4895

CVE-2026-4895 is a medium-severity vulnerability with a CVSS 3.x base score of 6.4. 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

The GreenShift - Animation and Page Builder Blocks plugin for WordPress is vulnerable to Stored Cross-Site Scripting in versions up to, and including, 12.8.9 This is due to insufficient input sanitization and output escaping in the gspb_greenShift_block_script_assets() function. The function uses str_replace() to insert 'fetchpriority="high"' before 'src=' attributes when processing greenshift-blocks/image blocks with the disablelazy attribute enabled. Because this replacement operates on the entire HTML string without parsing, contributors can inject the string 'src=' into HTML attribute values (such as class attributes). When the str_replace executes, the double quotes in the replacement string break out of the attribute context, allowing injection of malicious HTML attributes like onfocus with JavaScript payloads. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

Frequently asked questions

What is CVE-2026-4895?
The GreenShift - Animation and Page Builder Blocks plugin for WordPress is vulnerable to Stored Cross-Site Scripting in versions up to, and including, 12.8.9 This is due to insufficient input sanitization and output escaping in the gspb_greenShift_block_script_assets() function. The function uses str_replace() to insert 'fetchpriority="high"' before 'src=' attributes when processing greenshift-blocks/image blocks with the disablelazy attribute enabled. Because this replacement operates on the entire HTML string without parsing, contributors can inject the string 'src=' into HTML attribute values (such as class attributes). When the str_replace executes, the double quotes in the replacement string break out of the attribute context, allowing injection of malicious HTML attributes like onfocus with JavaScript payloads. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.
How severe is CVE-2026-4895?
CVE-2026-4895 has a CVSS 3.x base score of 6.4, 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 none.
Is CVE-2026-4895 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (34th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-4895?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-4895 have an EU (EUVD) identifier?
Yes. CVE-2026-4895 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-21647.
When was CVE-2026-4895 published?
CVE-2026-4895 was published on 2026-04-11 and last updated on 2026-06-17.

References

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

Browse all CWE-79 (Cross-site Scripting (XSS)) vulnerabilities →