CVE-2026-15697 in svg.js
Summary
by MITRE • 07/14/2026
A vulnerability was found in svgdotjs svg.js up to 3.2.5. This affects the function EventTarget.on of the file svgdotjs/svg.js of the component npm Package API. Performing a manipulation results in improperly controlled modification of object prototype attributes. The attack may be initiated remotely. The project was informed of the problem early through an issue report but has not responded yet.
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Analysis
by VulDB Data Team • 07/14/2026
This vulnerability resides within the svgdotjs svg.js javascript library version 3.2.5 and earlier, specifically targeting the EventTarget.on function implementation in the npm package API. The flaw constitutes a prototype pollution vulnerability that allows attackers to manipulate object prototype attributes through improper input validation during event handling operations. Such vulnerabilities fall under the CWE-1321 category for prototype pollution attacks, which represent a critical class of security flaws affecting javascript applications. The vulnerability manifests when malicious input is processed through the EventTarget.on method, enabling unauthorized modification of prototype properties that subsequently affect all instances of the affected objects.
The attack vector is remotely exploitable, meaning an adversary can trigger this vulnerability through network-based interactions without requiring local system access. This remote exploit capability significantly increases the threat surface and potential impact of the vulnerability. The issue stems from inadequate sanitization of user-supplied data when processing event listeners, allowing attackers to inject malicious prototype modifications that propagate throughout the application's object model. The vulnerability was initially reported through an issue tracker but has not yet received a response from the project maintainers, indicating a potential delay in addressing critical security concerns.
The operational impact of this vulnerability extends beyond simple denial of service scenarios, as prototype pollution can lead to more severe consequences including arbitrary code execution, authentication bypasses, and data manipulation. When attackers successfully pollute object prototypes, they can alter fundamental behaviors of javascript objects, potentially enabling them to manipulate application logic flow or access restricted functionality. This type of vulnerability represents a significant risk in web applications that rely heavily on user input processing and dynamic object creation patterns.
Mitigation strategies should focus on implementing comprehensive input validation and sanitization measures before processing any user-provided data within event handling functions. Organizations should consider updating to patched versions of the svg.js library immediately, while also implementing runtime protections such as prototype lockdown mechanisms and strict Content Security Policy enforcement. The ATT&CK framework categorizes this type of vulnerability under T1546.008 for 'Exploitation for Privilege Escalation' when used in conjunction with other attack vectors. Additionally, developers should adopt defensive programming practices including the use of Object.freeze() or Object.preventExtensions() on critical objects and implement proper input validation at multiple layers within their applications to prevent prototype pollution attacks from succeeding.