What happened

CISA added CVE-2020-11023 (jQuery XSS) to the Known Exploited Vulnerabilities catalog on 2025-01-23 CISA KEV. CISA sets a remediation due date of 2025-02-13 for impacted federal enterprises CISA KEV. The issue is a cross-site scripting flaw triggered when untrusted, malicious HTML is passed into jQuery’s DOM manipulation routines, enabling script execution in the user’s browser context NVD entry.

Why it matters

XSS enables attacker-controlled JavaScript to run in the victim’s session, exposing cookies, tokens, DOM-stored secrets, and allowing UI abuse and account takeover NVD entry. This entry is in CISA’s KEV, which signals observed exploitation in the wild and elevates the urgency to remediate on a fixed timeline CISA KEV. Because the flaw is in a ubiquitous front-end library, the blast radius includes any application that bundles or serves the affected jQuery builds until they are replaced or removed GHSA advisory.

Technical detail

The vulnerability is categorized under CWE-79 (Improper Neutralization of Input During Web Page Generation), i.e., cross-site scripting NVD entry. It manifests when HTML derived from untrusted input is enclosed in tags and passed to jQuery DOM manipulators (e.g., methods that inject or transform HTML), resulting in execution of attacker-supplied code in the browser context GHSA advisory. The CISA KEV description aligns: maliciously formed, untrusted HTML given to jQuery’s DOM manipulation can execute untrusted code in the user’s browser CISA KEV.

This is a client-side vulnerability in the jQuery library (open-source JavaScript), not a server-only bug, which means exploitation occurs when a rendered page assembles DOM with attacker-controlled HTML via the library GHSA advisory. The risk persists if applications store attacker-supplied HTML (e.g., comments, profiles) and later render it via jQuery manipulations, producing a persistent XSS condition NVD entry. CISA further notes this can impact open-source components used by multiple products, highlighting potential third-party dependency exposure chains CISA KEV.

Defense

• Patch/upgrade: Replace vulnerable jQuery builds with a vendor-fixed release as instructed by the project maintainers (remediation available via official security advisory) GHSA advisory.
• Code hygiene: Do not pass untrusted HTML to jQuery DOM manipulation methods; sanitize/encode and prefer text-based insertion paths when handling user data GHSA advisory.
• Exposure reduction: Inventory web assets to locate embedded/bundled jQuery versions and update all instances, including those nested in themes, CMS plugins, or vendor UIs CISA KEV.
• Deadline: Federal programs should meet CISA’s due date (2025-02-13) or otherwise discontinue use where mitigations are unavailable, per KEV guidance CISA KEV.

Verification and testing should confirm that no routes still render attacker-controlled HTML through jQuery paths, and that stale assets (CDN pins, legacy bundles) aren’t reintroducing the vulnerable code via caching or fallback loaders GHSA advisory.

Lyrie Verdict

This is a client-side injection vector that automated adversaries reliably weaponize. Lyrie flags vulnerable front-end dependencies at machine speed by fingerprinting served library versions and mapping them to KEV/CVE intelligence in real time CISA KEV. For CVE-2020-11023, we auto-correlate detections of jQuery on target paths with observed DOM-sink usage of untrusted HTML to elevate true risk, not just presence of the library NVD entry. That means autonomous prevention and prioritized response when we see exploitable flows—before a human analyst could triage the page, the route, and the library lineage GHSA advisory.