CVE-2019-9020

Public exploit available. Not confirmed exploited in the wild yet. A vendor fix is available.

CVSS 3.09.8Critical EPSS percentile95th10% chance in 30 days CISA KEVNot listedNo confirmed exploitation
Public exploit: 2 sources FixVendor fixNo build named by the sources

Published 2019-02-22Updated 2024-11-21Sources: CVE.org, NVD, BDU, CSAF

NVD CVE.org

What to do

The vendor has published a fix. Version details are below where the sources state them.

Steps

Written by AI from the record

Check whether your server/app runs PHP and which exact version (and whether the xmlrpc extension/functionality is enabled).
If your PHP version is older than the fixes listed below, schedule an upgrade as soon as possible.
Upgrade PHP to a fixed version: 5.6.40 or later, 7.1.26 or later, 7.2.14 or later, or 7.3.1 or later (as applicable to your branch).
Re-test your application’s XML-RPC usage (or disable XML-RPC if you don’t need it) after the upgrade.
If you can’t upgrade immediately, temporarily remove/disable xmlrpc functionality and block external access to any XML-RPC endpoints until the fix is applied.

sudo apt-get update && sudo apt-get install --only-upgrade php

Vendor advisory Usually a quick update

Check it yourselfA free OpenVAS check exists for this CVE. Run it against your hosts.Is your organisation exposed?Request an assessment to establish which checks fit your systems.

What it is

From the CVE record

An issue was discovered in PHP before 5.6.40, 7.x before 7.1.26, 7.2.x before 7.2.14, and 7.3.x before 7.3.1. Invalid input to the function xmlrpc_decode() can lead to an invalid memory access (heap out of bounds read or read after free). This is related to xml_elem_parse_buf in ext/xmlrpc/libxmlrpc/xml_element.c.

In plain language

Written by AI from the record

CVE-2019-9020 is a serious bug in older PHP versions that can crash or potentially let an attacker take control through malformed XML-RPC data; if your small business still runs an affected PHP version, you should act now.

CVE-2019-9020 is a memory-safety issue (CWE-125/CWE-416) in PHP’s xmlrpc_decode() path for ext/xmlrpc, where carefully crafted XML-RPC input can trigger invalid memory access (e.g., heap out-of-bounds read or read-after-free), making remote impact possible in vulnerable deployments; public exploits exist and the likelihood is rising.

If you're affected

Service crash (denial of service)
Potential PHP process compromise
Data exposure from memory reads
Business disruption for web apps

What is it

This vulnerability is in PHP, the software many websites use to run server-side code. If someone sends specially malformed XML-RPC messages, PHP may read memory it shouldn’t, which can crash the server or (in the worst case) lead to compromise. It’s like a door lock that sometimes breaks when someone jams it with the wrong shape of key.

Who is affected

This matters to you if your small business runs or hosts web applications using the PHP versions listed as vulnerable (before 5.6.40, 7.1.26, 7.2.14, or 7.3.1). It’s especially relevant if your app exposes XML-RPC functionality to the internet, because the bug is reachable through malformed XML-RPC input. Risk is present only if the vulnerable PHP code path is reachable (for example, if XML-RPC is enabled and an attacker can send requests to it).

How urgent is it

Attackers have public exploit code available, and exploitation likelihood is rising, which makes this a timely risk for exposed services. Because it’s tied to invalid memory access, it can cause immediate instability and potentially enable serious impact in vulnerable setups, so you should treat it as urgent (but not “wait-and-see” for every business).

What to do — in detail

Confirm exposure
- Identify all servers/environments where PHP is running (production, staging if it’s internet-exposed, and any internal web apps.
- Record the exact PHP version.
- Check whether XML-RPC is enabled/used (for example, whether your application exposes XML-RPC endpoints and/or loads the xmlrpc-related functionality).
Determine if you are affected
- Affected PHP versions are:
  - PHP before 5.6.40
  - PHP 7.x before 7.1.26
  - PHP 7.2.x before 7.2.14
  - PHP 7.3.x before 7.3.1
- If your version is within those ranges and XML-RPC input can reach xmlrpc_decode(), you should treat it as affected.
Apply the fix (target versions)
- Upgrade to the fixed PHP version for your branch:
  - Upgrade to 5.6.40 or later
  - Upgrade to 7.1.26 or later
  - Upgrade to 7.2.14 or later
  - Upgrade to 7.3.1 or later
- If you are on Debian and upgrading is supported via packages, follow the distribution’s update to the fixed PHP release.
Workaround if you cannot upgrade immediately
- Disable/remove XML-RPC functionality if your business app doesn’t require it.
- Block external network access to any XML-RPC endpoints until the fixed PHP version is installed.
After upgrading
- Re-test XML-RPC features (if used) to confirm normal operation.
- Watch logs for crashes or abnormal errors around XML-RPC requests.
Timeline guidance
- No CISA KEV listing was found in the provided findings, so follow your normal security change window—but given public exploits and rising likelihood, aim to complete remediation quickly.

Technical context

CVE-2019-9020 affects PHP’s XML-RPC decoding path (xmlrpc_decode(), linked to ext/xmlrpc/libxmlrpc/xml_element.c / xml_elem_parse_buf). The weakness is a memory-safety bug (CWE-125 and CWE-416) caused by invalid input leading to invalid memory access (heap out of bounds read or read after free). Public exploit code is available (weaponization indicates “2 known” public exploits), and press attention is rising; KEV is not listed. EPSS is reported as 10.1% with a rising trend, but public exploit availability and rising attention increase practical risk. KEV was not provided as a confirming exploitation signal in the findings, so urgency is based on the availability of public exploits and rising likelihood rather than a KEV-confirmed event.

This is a general assessment based on public vulnerability data. It does not account for your specific infrastructure — when in doubt, consult a security specialist.

Exploitation

Where each signal puts this CVE on the scale from published to confirmed exploited.

EPSS95th

Public exploit

CISA KEV

Not in the catalog. CISA has not confirmed exploitation.

Public exploits

2 sources with a proof of concept or module.

Exploit links, PoCs and Metasploit modules after sign-in

EPSS

10% chance of exploitation activity in the next 30 days, which ranks it in the 95th percentile of scored CVEs.

Exploit Prediction Scoring System, FIRST.org. A probability, not a confirmation.

Attention now

Rising.

Lifecycle

The patch came 471 days before any public exploit.

2026-09-23EPSS band changelow → moderateepss band change
2026-09-21EPSS band changemoderate → lowepss band change
2026-09-06EPSS band changelow → moderateepss band change
2026-09-05EPSS band changemoderate → lowepss band change
2026-08-31EPSS band changelow → moderateepss band change
2026-08-28EPSS band changemoderate → lowepss band change

Affected products

Novell Inc.commercial · US
phposs-project · USaka php language, pear, pecl
- phpDev ToolOSS Libraries / generic-library
debianoss-project · GBaka debian gnu/linux
- debian linuxOSOn-premOperating Systems / linux-distro
canonicalcommercial · GBaka canonical ltd.
- ubuntu linuxOSOn-premOperating Systems / linux-distro
netappcommercial · US
- storage automation storeHardware Firmware
opensuseoss-project · DE
- leapOSOn-premOperating Systems / linux-distro

And 4 more affected products. See all after sign-in

Technical detail

CVSS 3.0 vector

Open in the CVSS calculator

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Scored 9.8 by NVD.

How it is reached

Attack Vector NetworkExploitable remotely over the network without any special conditions
Attack Complexity LowNo special conditions — the attack can be reliably reproduced
Privileges Required NoneNo authentication required — anyone can exploit this
User Interaction NoneNo user interaction needed — fully automated exploitation

Scope

Scope UnchangedImpact is limited to the vulnerable component itself

Impact if exploited

Confidentiality HighTotal information disclosure — all data in the component is compromised
Integrity HighTotal loss of integrity — attacker can modify any data in the component
Availability HighTotal denial of service — the component is completely unavailable