CVE-2024-43398: REXML is an XML toolkit for Ruby

Q: How do I fix CVE-2024-43398?

rexml: upgrade to 3.3.6; bootstrap os: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Q: Is CVE-2024-43398 being exploited?

CVE-2024-43398 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-2024-43398 affect?

CVE-2024-43398 affects rexml, bootstrap os. Severity is medium (CVSS 5.9). REXML is an XML toolkit for Ruby. The REXML gem before 3.3.6 has a DoS vulnerability when it parses an XML that has many deep elements that have same local name attributes. If you need to parse untrusted XMLs with tree parser API like REXML

Q: How urgent is CVE-2024-43398?

Priority 43/100. Remotely exploitable, no login, no user action

This month

MEDIUM 5.9REMOTEUPGRADEMITIGATE

CVE-2024-43398 is a medium-severity flaw (CVSS 5.9) affecting rexml, bootstrap os. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

REXML is an XML toolkit for Ruby. The REXML gem before 3.3.6 has a DoS vulnerability when it parses an XML that has many deep elements that have same local name attributes. If you need to parse untrusted XMLs with tree parser API like REXML::Document.new, you may be impacted to this vulnerability. If you use other parser APIs such as stream parser API and SAX2 parser API, this vulnerability is not affected. The REXML gem 3.3.6 or later include th

Why this priority

Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	5.9 (Medium)
Attack vector	Network (remote)
Attack complexity	High
Privileges needed	None
User interaction	None
EPSS exploit chance	1.2% (top 32%)
CISA exploited list	No
Weakness	CWE-776
Published	2024-08-22
Last modified	2026-06-17

Publisher (CNA): GitHub, Inc. · Vendor: netapp · ruby-lang

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

Am I affected?

Timeline

2024-08-22 15:15 UTCPublished CVE record published
2026-06-17 07:50 UTCUpdated Record last modified

ruby-lang rexml UPGRADE

Affected: < 3.3.6

Fixed in: 3.3.6

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to 3.3.6 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade rexml

Note

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

netapp bootstrap os MITIGATE

Affected: all versions

Fixed in: no fixed release known

Safe to downgrade to: no unaffected older release

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.

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-2024-43398?

rexml: upgrade to 3.3.6; bootstrap os: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2024-43398 being exploited?

CVE-2024-43398 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-2024-43398 affect?

CVE-2024-43398 affects rexml, bootstrap os. Severity is medium (CVSS 5.9). REXML is an XML toolkit for Ruby. The REXML gem before 3.3.6 has a DoS vulnerability when it parses an XML that has many deep elements that have same local name attributes. If you need to parse untrusted XMLs with tree parser API like REXML

How urgent is CVE-2024-43398?

Priority 43/100. Remotely exploitable, no login, no user action

Software pages

Ruby vulnerabilities · Bootstrap vulnerabilities

Related CVEs

CVE-2024-49761 HIGH 7.5 UPGRADE DOWNGRADE REXML is an XML toolkit for Ruby
CVE-2024-41946 MEDIUM 5.3 UPGRADE REXML is an XML toolkit for Ruby
CVE-2024-41123 MEDIUM 5.3 UPGRADE REXML is an XML toolkit for Ruby
CVE-2024-39908 MEDIUM 4.3 UPGRADE MITIGATE REXML is an XML toolkit for Ruby
CVE-2024-35176 MEDIUM 5.3 UPGRADE REXML is an XML toolkit for Ruby

References

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