CVE-2020-5529: HtmlUnit prior to 2.37.0 contains code execution vulnerabilities

Q: How do I fix CVE-2020-5529?

htmlunit: upgrade to 2.37.0; debian linux: mitigate or apply the listed mitigation; ubuntu linux: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Q: Is CVE-2020-5529 being exploited?

CVE-2020-5529 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2020-5529 affect?

CVE-2020-5529 affects htmlunit, debian linux, ubuntu linux. Severity is high (CVSS 8.1). HtmlUnit prior to 2.37.0 contains code execution vulnerabilities. HtmlUnit initializes Rhino engine improperly, hence a malicious JavScript code can execute arbitrary Java code on the application. Moreover, when embedded in Android applicat

Q: How urgent is CVE-2020-5529?

Priority 61/100. High severity; EPSS top 8%: very likely to be exploited; Remotely exploitable, no login, no user action; On your watchlist

This week

HIGH 8.1REMOTEWATCHLISTUPGRADEMITIGATEMITIGATE

CVE-2020-5529 is a high-severity flaw (CVSS 8.1) affecting htmlunit, debian linux, ubuntu linux. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

HtmlUnit prior to 2.37.0 contains code execution vulnerabilities. HtmlUnit initializes Rhino engine improperly, hence a malicious JavScript code can execute arbitrary Java code on the application. Moreover, when embedded in Android application, Android-specific initialization of Rhino engine is done in an improper way, hence a malicious JavaScript code can execute arbitrary Java code on the application.

Why this priority

High severity
EPSS top 8%: very likely to be exploited
Remotely exploitable, no login, no user action
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	8.1 (High)
Attack vector	Network (remote)
Attack complexity	High
Privileges needed	None
User interaction	None
EPSS exploit chance	4.7% (top 8%)
CISA exploited list	No
Weakness	CWE-665, CWE-94
Published	2020-02-11
Last modified	2026-06-17

Publisher (CNA): JPCERT/CC · Vendor: apache · canonical · debian · htmlunit

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2020-02-11 12:15 UTCPublished CVE record published
2026-06-17 03:21 UTCUpdated Record last modified

htmlunit htmlunit UPGRADE

Affected: < 2.37.0

Fixed in: 2.37.0

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy htmlunit || rpm -q htmlunit || htmlunit --version

2. UPGRADE to 2.37.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade htmlunit

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade htmlunit

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

debian debian linux MITIGATE

Affected: 9.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 9.0

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

canonical ubuntu linux MITIGATE

Affected: 16.04

Fixed in: no fixed release known

Safe to downgrade to: a release before 16.04

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

apache camel MITIGATE

Affected: all versions

Fixed in: no fixed release known

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy camel || rpm -q camel || camel --version

No fixed or unaffected release known

Apply the vendor mitigation from the advisory, disable the affected feature, or restrict network access.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2020-5529?

htmlunit: upgrade to 2.37.0; debian linux: mitigate or apply the listed mitigation; ubuntu linux: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2020-5529 being exploited?

CVE-2020-5529 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2020-5529 affect?

CVE-2020-5529 affects htmlunit, debian linux, ubuntu linux. Severity is high (CVSS 8.1). HtmlUnit prior to 2.37.0 contains code execution vulnerabilities. HtmlUnit initializes Rhino engine improperly, hence a malicious JavScript code can execute arbitrary Java code on the application. Moreover, when embedded in Android applicat

How urgent is CVE-2020-5529?

Priority 61/100. High severity; EPSS top 8%: very likely to be exploited; Remotely exploitable, no login, no user action; On your watchlist

Software pages

Java vulnerabilities · Ubuntu vulnerabilities · Debian vulnerabilities · Android vulnerabilities

Related CVEs

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CVE-2023-2798 HIGH 7.5 UPGRADE Those using HtmlUnit to browse untrusted webpages may be vulnerable to Denial of service attacks (DoS)
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References

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