Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain
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AccessReach CXF web service endpoint
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DeliveryCraft oversized XML/SOAP document
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ExploitSubmit request triggering DOM build (SAAJ/WS-Security)
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ExecutionUnbounded parsing exhausts memory and CPU
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ImpactService denial of service
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A02:2025 - Security Misconfiguration
ASVS 5.0
V13 - Configuration XML entity recursion limits
|
| Exploitation Conditions | Requires a reachable Apache CXF web-service endpoint that parses attacker-supplied XML and builds a DOM - specifically the SAAJ or WS-Security processing paths - running a version prior to 4.2.4, 4.1.9, or 3.6.13. The vendor explicitly scopes the DoS to deployments where 'no request size limit was configured,' so the primary limiting factor is the presence of any upstream or container-level request-size cap (reverse proxy, API gateway, or servlet max-post-size), which largely neutralizes the issue. No authentication is inherently required by the parsing flaw itself, but exposure depends on whether the vulnerable endpoint is publicly reachable and unauthenticated in a given deployment. |
| Impact | No CVSS vector, EPSS score, KEV listing, or POC is provided in the input, so quantitative exploitation signals are entirely absent and risk must be inferred from the description alone. The flaw is a memory/CPU exhaustion denial-of-service in Apache CXF's StaxUtils: by default no cap existed on XML element count or character count, so an oversized XML body consumed excessive resources during parsing - especially where CXF builds a DOM (SAAJ or WS-Security). Based on the description this is a network-reachable, low-complexity, availability-only issue (my independent assessment: AV:N/AC:L/PR:N/UI:N/A:H, approximately 7.5), which would normally rate HIGH. However, real-world risk is tempered by a key limiting condition stated in the advisory itself: the DoS occurs 'when no request size limit was configured,' so deployments fronted by a reverse proxy, gateway, or servlet container request-size limit are substantially less exposed. There is no confidentiality or integrity impact. Exploitation status: no public exploit identified at time of analysis, and no evidence of active exploitation. Net assessment: a legitimate availability risk for internet-facing CXF SOAP/WS-Security endpoints lacking size limits, but not an urgent actively-exploited priority - patch in a normal cycle and verify upstream size limits. |
| Exploit ScenarioDerived | An attacker sends a single very large XML/SOAP request (millions of elements or a multi-hundred-megabyte document) to a CXF-based web service endpoint that builds a DOM for SAAJ or WS-Security processing. With no element-count or character limit and no request-size limit configured, parsing exhausts heap and CPU, degrading or crashing the service for legitimate users. No public exploit is identified at time of analysis, though crafting such a payload is trivial. |
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Alert meAnalysisAIv1 – Oct 09, 2026
Apache CXF versions prior to 4.2.4, 4.1.9, and 3.6.13 allow remote, unauthenticated attackers to cause a denial of service by submitting a very large XML document that exhausts memory and CPU during parsing. The flaw lies in StaxUtils, which by default imposes no limit on the total number of elements or characters, and is most impactful when CXF builds a DOM from the input, such as in SAAJ or WS-Security processing. No public exploit code has been identified, and deployments that enforce a request size limit are largely protected.
RemediationAI
Vendor-released patch: upgrade to Apache CXF 4.2.4, 4.1.9, or 3.6.13. If upgrading is not immediately possible, configure the new limits explicitly by setting the system properties org.apache.cxf.stax.maxElementCount and org.apache.cxf.stax.maxXMLCharacters to values appropriate for your application, but be aware that raising the limits increases memory consumption and does not eliminate the underlying risk. Deploying a request size limit at an upstream reverse proxy, API gateway, or servlet container (e.g., maxPostSize) will also mitigate the issue by rejecting oversized XML payloads before they reach CXF. Consult the advisory at https://lists.apache.org/thread.html/ms2gbpof609o0v1bjlzb1rn7fwh61l1j for details.
Affected VersionsENISA
Affected Packages
Source: OSV (Open Source Vulnerabilities)
Affects your stack
Affects 1 package in euvd
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Technical ContextAI · show details
Apache CXF is a Java framework for building web services. The vulnerability resides in the StaxUtils component, which uses the Streaming API for XML (StAX) to parse incoming XML. By default, StaxUtils did not restrict the total element count or document size, so a maliciously large XML request could force the parser to allocate excessive memory and consume CPU cycles, leading to resource exhaustion. The risk is heightened when CXF constructs a DOM from the input - for example, in SOAP with Attachments API for Java (SAAJ) or WS-Security handlers - because DOM parsing holds the entire document in memory. No CWE identifier was provided in the input, but the flaw class is consistent with uncontrolled resource consumption (CWE-400). The new defaults cap the maximum element count at 100 times maxChildElements (5,000,000 by default) and the maximum document size at 256 million characters, configurable via org.apache.cxf.stax.maxElementCount and org.apache.cxf.stax.maxXMLCharacters.
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Severity by source
Sources disagree (Low–High)AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Network-reachable XML endpoint, trivially crafted oversized payload (AC:L), no auth or interaction needed for parsing; impact is availability-only resource exhaustion, so C:N/I:N/A:H.
vuln.today treats the vendor’s rating as authoritative. A higher third-party CVSS (e.g. CISA-ADP) is shown for transparency but does not drive the headline severity.
CVSS VectorVendor: apache
Lifecycle Timeline
3DescriptionCVE.org
By default, StaxUtils placed no limit on the total number of elements or the total number of characters in an XML document. A very large request could therefore use a lot of memory and CPU during parsing, especially where CXF builds a DOM from the input (for example SAAJ or WS-Security), and could cause a denial of service when no request size limit was configured. Both limits now have defaults: the maximum element count is 100 × maxChildElements (5,000,000 by default), and the maximum document size is 256M characters. Applications that process larger documents can raise the limits with the org.apache.cxf.stax.maxElementCount and org.apache.cxf.stax.maxXMLCharacters properties. Users are recommended to upgrade to versions 4.2.4 or 4.1.9 or 3.6.13, which fix this issue.
Threat Intelligence Overview
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
Denial of Service attacks render applications or systems unavailable by overwhelming resources or triggering failure conditions.
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NVD
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EPSS
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