CVE-2026-44966

CVE-2026-44966 is a high-severity vulnerability in Shepherdwind Velocity.js with a CVSS 3.x base score of 8.3. 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-1321.

Key facts

Description

Velocity.js is a JavaScript implementation of the Apache Velocity template engine. In 2.1.5 and earlier, a prototype pollution vulnerability was discovered in velocityjs. This issue occurs during the processing of #set directives in Velocity templates. If an application renders a template controlled by an attacker, it is possible to modify Object.prototype, potentially leading to Denial of Service (DoS) or Remote Code Execution (RCE) depending on the server environment.

Frequently asked questions

What is CVE-2026-44966?
Velocity.js is a JavaScript implementation of the Apache Velocity template engine. In 2.1.5 and earlier, a prototype pollution vulnerability was discovered in velocityjs. This issue occurs during the processing of #set directives in Velocity templates. If an application renders a template controlled by an attacker, it is possible to modify Object.prototype, potentially leading to Denial of Service (DoS) or Remote Code Execution (RCE) depending on the server environment.
How severe is CVE-2026-44966?
CVE-2026-44966 has a CVSS 3.x base score of 8.3, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability low.
Is CVE-2026-44966 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (40th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-44966?
CVE-2026-44966 affects Shepherdwind Velocity.js. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-44966?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-44966 have an EU (EUVD) identifier?
Yes. CVE-2026-44966 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-32007.
When was CVE-2026-44966 published?
CVE-2026-44966 was published on 2026-05-26 and last updated on 2026-06-17.

References

Affected products (1)

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