VulnerabilityPublished 16 May 2024Updated 3 Nov 2025

CVE-2024-35176: ruby rexml · Uncontrolled Resource Consumption

Affects ruby rexmlSource CVE Database V5

Not known to be exploited · CVSS 5.3 Medium : upgrade to 3.2.7 when convenient.

Data as of 26 Oct 2026, 09:15 UTC

CVSS 3.1 base score

5.3Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 2.0% chance of exploitation in 30 days – higher than 81% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 3.2.7

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: None
Availability: Low

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: Low: Performance is reduced or there are interruptions in resource availability. Even if repeated exploitation of the vulnerability is possible, the attacker does not have the ability to completely deny service to legitimate users. The resources in the impacted component are either partially available all of the time, or fully available only some of the time, but overall there is no direct, serious consequence to the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 16 May 2024
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade ruby rexml to 3.2.7.

Affected software

Product	Affected	Fixed in
RubyGemsrexml`pkg:gem/rexml`Other threats	Affected <3.2.7	Fixed in 3.2.7

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

1. Upgrade all Ruby environments using the REXML gem to version 3.2.7 or later immediately to apply the official patch. 2. Audit all applications and services that parse XML data to identify usage of vulnerable REXML versions. 3. Implement input validation and sanitization to reject XML inputs containing suspiciously large numbers of '<' characters or other malformed constructs before parsing. 4. Where possible, avoid parsing XML from untrusted or unauthenticated sources. 5. Introduce resource limits and timeouts on XML parsing operations to prevent excessive CPU or memory consumption. 6. Monitor application logs and resource usage metrics for signs of abnormal spikes during XML processing. 7. Employ Web Application Firewalls (WAFs) or XML gateways that can detect and block malicious XML payloads targeting this vulnerability. 8. Educate development teams about secure XML parsing practices and the risks of uncontrolled resource consumption. 9. Establish incident response plans to quickly address denial of service events related to XML parsing. 10. Regularly review and update dependencies to incorporate security patches promptly.

Description

REXML is an XML toolkit for Ruby. The REXML gem before 3.2.6 has a denial of service vulnerability when it parses an XML that has many `<`s in an attribute value. Those who need to parse untrusted XMLs may be impacted to this vulnerability. The REXML gem 3.2.7 or later include the patch to fix this vulnerability. As a workaround, don't parse untrusted XMLs.

Impact

For European organizations, this vulnerability primarily threatens the availability of services relying on Ruby applications that use the REXML gem for XML parsing. Denial of service attacks exploiting this vulnerability could disrupt business-critical applications, especially those processing XML data from external or untrusted sources, such as web services, APIs, or integration platforms. This could lead to downtime, degraded performance, and potential loss of customer trust. Sectors such as finance, healthcare, government, and telecommunications, which often handle XML-based data exchanges, may face operational interruptions. Additionally, organizations with automated workflows or DevOps pipelines using Ruby scripts for XML processing might experience cascading failures. While confidentiality and integrity are not directly impacted, the availability disruption could have significant operational and reputational consequences. The medium CVSS score (5.3) reflects moderate severity, but the ease of exploitation without authentication increases the risk profile. Proactive mitigation is essential to prevent service outages and maintain compliance with European cybersecurity regulations.

Summary

CVE-2024-35176 is a denial of service (DoS) vulnerability classified under CWE-400 (Uncontrolled Resource Consumption) and CWE-770 (Allocation of Resources Without Limits or Throttling) affecting the Ruby REXML gem versions prior to 3.2.7. REXML is a pure Ruby XML toolkit widely used for XML parsing. The vulnerability occurs when REXML parses XML documents containing attribute values with a large number of '<' characters. This malformed input causes excessive resource consumption, such as CPU and memory, leading to application slowdown or crash, effectively resulting in a denial of service. The vulnerability can be triggered remotely without requiring authentication or user interaction, making it exploitable in network-facing applications that parse untrusted XML inputs. The root cause is insufficient input validation and lack of resource usage limits during XML parsing. The issue was addressed in REXML version 3.2.7 by implementing proper input handling and resource consumption controls. No public exploits have been reported yet, but the vulnerability's nature makes it a credible threat to availability in affected environments. Organizations using REXML in Ruby applications that handle untrusted XML should prioritize upgrading to version 3.2.7 or later. As a temporary mitigation, avoiding parsing untrusted XML inputs can reduce exposure.

CWE-400Uncontrolled Resource Consumption (opens in a new tab)
Class weaknessLikelihood of exploit: High
The product does not properly control the allocation and maintenance of a limited resource.
MITRE discourages mapping vulnerabilities to this broad entry; the root cause is usually a more specific weakness.
Architecture and Design
Design throttling mechanisms into the system architecture. The best protection is to limit the amount of resources that an unauthorized user can cause to be expended. A strong authentication and access control model will help prevent such attacks from occurring in the first place.
Architecture and Design
Mitigation of resource exhaustion attacks requires that the target system either: recognizes the attack and denies that user further access for a given amount of time, or; uniformly throttles all requests in order to make it more difficult to consume resources more quickly than they can again be freed.
Architecture and Design
Ensure that protocols have specific limits of scale placed on them.
OWASP Cheat Sheets
File Upload (opens in a new tab)
OWASP ASVS 4.0.3
V12.1.1 (opens in a new tab)
Attack patterns
XML Ping of the Death (opens in a new tab)
Regular Expression Exponential Blowup (opens in a new tab)
Sustained Client Engagement (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
CWE-770Allocation of Resources Without Limits or Throttling (opens in a new tab)
Base weaknessLikelihood of exploit: HighCWE Top 25 (2025): #25
The product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated.
Requirements
Clearly specify the minimum and maximum expectations for capabilities, and dictate which behaviors are acceptable when resource allocation reaches limits.
Architecture and Design
Limit the amount of resources that are accessible to unprivileged users. Set per-user limits for resources. Allow the system administrator to define these limits. Be careful to avoid CWE-410.
Architecture and Design
Design throttling mechanisms into the system architecture. The best protection is to limit the amount of resources that an unauthorized user can cause to be expended.
OWASP Cheat Sheets
Abuse Case (opens in a new tab)
OWASP ASVS 4.0.3
V8.1.4 (opens in a new tab)
V13.4.1 (opens in a new tab)
V11.1.4 (opens in a new tab)
Attack patterns
XML Ping of the Death (opens in a new tab)
Exponential Data Expansion (opens in a new tab)
Serialized Data Parameter Blowup (opens in a new tab)
Serialized Data with Nested Payloads (opens in a new tab)
Oversized Serialized Data Payloads (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 3 Nov 2025, 22:15 UTC

WeaknessesCWE-400, CWE-770

Technical details

References

Community reviews

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