⚠ Reference material — not professional advice. Test in staging, back up first, verify against your specific version. Use your own judgment for your environment.
● Medium · CVSS 6.9 ⚠ ACTIVELY EXPLOITED — CISA KEV

How to Fix CVE-2020-11023: Cross-Site Scripting in jQuery

By Sai Kiran Pandrala

⚡ At a glance
SeverityCVSS 6.9 - Medium
Actively exploited?Yes, listed in CISA KEV (added 2025-01-23)
AffectedjQuery >= 1.0.3, < 3.5.0
Fixed inSee vendor advisory
Type (CWE)CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Patch immediately. CISA added CVE-2020-11023 to the Known Exploited Vulnerabilities catalog on 2025-01-23. Federal civilian agencies must remediate by 2025-02-13. Treat every internet-reachable instance as a priority patch.

What is CVE-2020-11023?

CVE-2020-11023 is a Cross-Site Scripting flaw in jQuery. It carries a CVSS base score of 6.9 (medium). CISA confirmed real-world exploitation by adding it to the Known Exploited Vulnerabilities catalog on 2025-01-23.

From the source record: In jQuery versions greater than or equal to 1.0.3 and before 3.5.0, passing HTML containing <option> elements from untrusted sources - even after sanitizing it - to one of jQuery's DOM manipulation methods (i.e. .html(), .append(), and others) may execute untrusted code. This problem is patched in jQuery 3.5.0.

Why it matters in practice: KEV-listed CVEs draw continuous internet-wide scanning. Any unpatched, internet-reachable installation is on borrowed time. The blast radius depends on how the affected service is exposed. An internet-facing instance with no compensating controls is the highest-risk configuration.

Am I affected?

You are affected if your installation of jQuery matches a version listed in the Affected row above.

Check the installed version of jQuery against the Affected row above. If the version sits at or below the affected range and the vendor patch has not been applied, you are vulnerable.

How to fix CVE-2020-11023

Apply the vendor patch. Target the patched build listed on the vendor advisory. The runnable command set below covers the most common deployment patterns for jQuery.

Generic upgrade path


# Debian / Ubuntu
sudo apt-get update && sudo apt-get install --only-upgrade jquery
# RHEL / Rocky / Alma
sudo dnf upgrade --security -y
# Windows
# PowerShell:
#   winget upgrade --all --silent --accept-package-agreements --accept-source-agreements
# macOS
sudo softwareupdate -i -a -R

After applying the patch

  1. Restart the service or device so the patched binary loads.
  2. Confirm the running version matches the Fixed in row using the verification command below.
  3. Rotate credentials and API keys that the affected service could access if the asset was exposed during the disclosure window.

If you can't patch immediately

Until the patch lands, narrow the attack surface with these runnable controls.

Reduce the attack surface

Restrict network reach to the affected service to the smallest set of hosts that must access it. On Linux:


# Vendor advisory: https://github.com/jquery/jquery/security/advisories/GHSA-jpcq-cgw6-v4j6
sudo iptables -A INPUT -p tcp --dport <service-port> -s 10.10.10.0/24 -j ACCEPT
sudo iptables -A INPUT -p tcp --dport <service-port> -j DROP

On Windows:


# Vendor advisory: https://github.com/jquery/jquery/security/advisories/GHSA-jpcq-cgw6-v4j6
New-NetFirewallRule -DisplayName "Block CVE-2020-11023 inbound" -Direction Inbound -Action Block -Protocol TCP -LocalPort <service-port>

Mitigations are temporary. Apply the vendor patch as soon as a maintenance window opens.

How to verify the fix worked

Confirm the patched build is the one actually running.

Run the product's --version or about command and compare against the Fixed in row (See vendor advisory). Re-run an authenticated vulnerability scan and confirm the scanner no longer flags CVE-2020-11023.

Also worth doing: pull recent log windows for any indicators of compromise listed in the vendor advisory, and re-run an authenticated vulnerability scan with up-to-date signatures.

Frequently asked questions

Other vulnerabilities in the same area that are worth patching alongside this one:

Is CVE-2020-11023 being exploited in the wild?

Yes. CISA added CVE-2020-11023 to the Known Exploited Vulnerabilities catalog on 2025-01-23. KEV listing means at least one confirmed real-world exploitation report exists.

Do I have to take downtime to patch?

For most jQuery deployments, the patched build needs a service restart or device reboot. HA pairs and clusters can roll the upgrade by patching the standby first, failing over, then patching the former primary.

Will a WAF or IDS rule alone close CVE-2020-11023?

No. Network filters cut down opportunistic scans but they do not remove the flaw. The vendor patch is the only durable fix.

How quickly should I act on CVE-2020-11023?

Within the standard patch cycle if the asset is internal-only. Inside one to two weeks for any internet-facing instance, sooner if compensating controls are not in place.

References

*Assembled from the official vendor advisory, the NVD record, and the CISA KEV listing on 2026-05-25. Always confirm against the vendor advisory before applying changes in production.*