CVE-2024-43398 | REXML denial of service vulnerability

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 the patch to fix the vulnerability.

Published: 2024-08-22 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2024-43398 is rated Moderate Risk (46.1/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 1.21%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2024-43398

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 1.14% 1.21% +0.07%
2 2026-06-11 1.17% 1.14% -0.03%
3 2026-05-28 — 1.17% —

Full EPSS history (45 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2024-43398

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.9 3.1 MEDIUM
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.2 3.6 [email protected]

Weakness enumeration for CVE-2024-43398

GitHub Security Advisory for CVE-2024-43398

GHSA-vmwr-mc7x-5vc3 · Severity: high · Ecosystem: rubygems — REXML denial of service vulnerability

OS Trackers for CVE-2024-43398

vendor priority summary link
alpine medium CVE-2024-43398: 1 source package rows (ruby-rexml); 5 state rows across 5 repos (3.19-main, 3.20-main, 3.21-main, 3.22-main, edge-main); fixed 5, open 0. https://security.alpinelinux.org/vuln/CVE-2024-43398
debian not yet assigned CVE-2024-43398 not yet assigned priority: Debian including 3 source packages (ruby2.7, ruby3.1, ruby3.3), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 4, open 1. https://security-tracker.debian.org/tracker/CVE-2024-43398
gentoo normal CVE-2024-43398: 1 GLSA(s) (202507-08), 1 atom(s) (dev-ruby/rexml); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2024-43398
redhat medium — https://access.redhat.com/security/cve/CVE-2024-43398
suse high CVE-2024-43398 severity important: SUSE including 323 source package names (2.19-54.2:libruby2_5-2_5-2.5.9-150000.4.32.1, 2.19-54.2:ruby2.5-2.5.9-150000.4.32.1, …), 932 product×package rows across 190 product lines (Container bci/ruby, Container suse/rmt-server, … (190 product lines)): Fixed 619, Known Affected 231, Known Not Affected 82. https://www.suse.com/security/cve/CVE-2024-43398/
ubuntu low CVE-2024-43398 low priority: Ubuntu including 6 source packages (ruby2.3, ruby2.5, ruby2.7, ruby3.0, ruby3.2, ruby3.3), 44 status rows across 9 suites (bionic, focal, jammy, noble, oracular, plucky, questing, upstream, xenial): DNE 30, needs-triage 7, released 7. https://ubuntu.com/security/CVE-2024-43398

Affected software / configurations for CVE-2024-43398

Vendor Product Version Raw CPE
ruby-lang rexml < 3.3.6 cpe:2.3:a:ruby-lang:rexml:*:*:*:*:*:ruby:*:*
netapp bootstrap_os — cpe:2.3:o:netapp:bootstrap_os:-:*:*:*:*:*:*:*

References for CVE-2024-43398

cvelogic Threat Intelligence