Improper Restriction of Recursive Entity References in DTDs ('XML Entity Expansion')

libexpat through 2.9.0 contains a denial of service vulnerability because billion laughs protection in accountingDiffTolerated() in xmlparse.c detects entity amplification too late. Attackers can supply a moderately sized XML document with a large DTD and nested entity expansions to consume tens of seconds of CPU per parse.Show less

PhpSpreadsheet is a pure PHP library for reading and writing spreadsheet files. Prior to 1.30.7, 2.1.19, 2.4.8, 3.10.8, and 5.10.0, XmlScanner::scan in src/PhpSpreadsheet/Reader/Security/XmlScanner.php uses a DOCTYPE detection pattern that accounts for NUL-byte interleaving but not ISO-2022 escape sequences in XLSX XML parts. The escape sequences prevent the scanner from matching the declaration, and XML charset normalization then removes the escape bytes before parsing, exposing a valid DOCTYPE and entity definitions. Processing an attacker-controlled XLSX can therefore cause entity-expansion denial of service on supported PHP versions and can permit local file access or SSRF on PHP before 8.0 or when LIBXML_NOENT is enabled. This issue is fixed in versions 1.30.7, 2.1.19, 2.4.8, 3.10.8, and 5.10.0.Show less

PhpSpreadsheet is a pure PHP library for reading and writing spreadsheet files. From 3.3.0 until 3.10.8 and 5.10.0, Reader\Xml passes stored SpreadsheetML XML through XmlScanner::scan in Xml::canRead and Xml::trySimpleXMLLoadStringPrivate, while Xml::unentity decodes numeric entities only after each DOCTYPE pattern check. A double-encoded less-than character is reduced by the first callback to another encoded character and by the second callback to a literal less-than sign, so SimpleXML receives an unchecked DOCTYPE and entity declaration. Processing attacker-controlled SpreadsheetML XML can cause entity-expansion denial of service and can permit local file access or SSRF on PHP before 8.0 or when LIBXML_NOENT is enabled. This issue is fixed in versions 3.10.8 and 5.10.0.Show less

** UNSUPPORTED WHEN ASSIGNED ** Improper restriction of recursive entity references in DTDs ('XML entity expansion') vulnerability in Apache Cocoon. This issue affects Apache Cocoon: all versions. XEE in the fp: form processor could lead to SSRF, including exposing files from the server to an untrusted external system As this project is retired, we do not plan to release a version that fixes this issue. Users are recommended to find an alternative or restrict access to the instance to trusted users. NOTE: This vulnerability only affects products that are no longer supported by the maintainer.Show less

A denial of service vulnerability exists in the XML parsing of multiple versions of OpenNMS Meridian and Horizon. OpenNMS parsed XML without an effective limit on entity expansion. A document with a DOCTYPE that declares internal entities can expand to a very large value and exhaust the server memory. An authenticated user with provisioning access can supply such a document through a requisition or foreign-source import, which includes a remote requisition URL that the server fetches and parses. Both deeply nested entities and a single large entity referenced many times cause the memory exhaustion. The fix caps the number of entity expansions for all XML parsing and rejects any DOCTYPE in requisition and foreign-source XML. The solution is to upgrade to Meridian 2024.3.14, 2025.0.11, 2026.0.1 and Horizon 36.0.5 or newer. Meridian and Horizon installation instructions state that they are intended for installation within an organization's private networks and should not be directly accessible from the Internet.Show less

Wazuh from 3.9.0 before 4.14.8 contains an uncontrolled YAML alias expansion vulnerability in yaml2json_node that allows a manager-controlled policy to exhaust agent memory. Attackers controlling the manager can push a small SCA policy with nested aliases via merged.mg to OOM-kill wazuh-modulesd on every agent in a group.Show less

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.Show less

Improper restriction of recursive entity references in DTDs ('XML entity expansion') vulnerability in Apache Sling XSS. This issue affects Apache Sling XSS: before 2.4.12. Users are recommended to upgrade to version 2.4.12, which fixes the issue.Show less

ArcadeDB is a Multi-Model DBMS. Prior to 26.6.1, the IMPORT DATABASE statement in engine/src/main/java/com/arcadedb/query/sql/parser/ImportDatabaseStatement.java did not require administrative privileges and passed its source to integration/src/main/java/com/arcadedb/integration/importer/SourceDiscovery.java without validation. An authenticated user with SQL command access through /api/v1/command or /api/v1/query can supply HTTP or HTTPS destinations to make server-side requests to internal services, or file:// paths to read files accessible to the server process and ingest the results as queryable records. The XML importer also permits DTD processing and external entities, enabling entity expansion. The root-only /api/v1/server administration endpoint is not affected. The fix requires updateSecurity permission, blocks local-network import destinations by default through arcadedb.server.security.importBlockLocalNetworks, supports the arcadedb.server.security.importAllowedLocalPaths file allow-list, and disables XML DTD processing and external entities. This issue is fixed in version 26.6.1.Show less

SAP Process Integration (SOAP Adapter) allows a privileged user to send specially crafted requests containing deeply nested entity definitions, which under certain conditions could temporarily increase processor load and degrade system responsiveness. Successful exploitation results in low impact on availability with no impact on confidentiality and integrity.Show less

IBM App Connect Enterprise 13.0.1.0 through 13.0.8.1, and 12.0.1.0 through 12.0.12.28 and IBM Integration Bus for z/OS 10.1.0.0 through 10.1.0.7 Toolkit could allow an authenticated user to cause a denial-of-service condition due to improper validation of XML entities.Show less

NLTK versions before 3.10.3 use xml.etree.ElementTree to parse XML in multiple modules, which honors entity declarations in document DTDs. Attackers can craft XML payloads with nested entity declarations that expand from hundreds of bytes to megabytes in memory, causing denial of service.Show less

fast-xml-parser allows users to process XML from JS object without C/C++ based libraries or callbacks. From 5.9.3 until 5.10.1, src/xmlparser/OrderedObjParser.js processes multiple DOCTYPE declarations within a single XML document and passes each declaration's entities through addInputEntities(). addInputEntities() resets maxTotalExpansions and maxExpandedLength every time it is called, allowing additional DOCTYPE declarations to repeatedly reset the configured entity-expansion limits during one parse operation. A crafted XML document can then cause excessive CPU use, event-loop blocking, memory exhaustion, and process termination. This issue is fixed in version 5.10.1.Show less

The XML and schema validation functionalities within the SchemaValidator Mediator process XML input as part of validation flows. Under certain conditions, the XML parser allows the resolution of external entities when handling user-supplied XML content during validation operations. This behavior can occur when an attacker supplies crafted XML payloads to the relevant mediator flows with sufficient privileges. Successful exploitation may allow a highly privileged actor to read files accessible within the server hosting the affected product. Additionally, it may be possible to trigger outbound requests to unintended internal or external locations, depending on the server environment and network configuration. Specially crafted XML payloads can also lead to excessive resource consumption during parsing, impacting the availability of the product.Show less

In Progress® Telerik® UI for AJAX prior to v2026.2.708, the internal LayoutBuilder control processes client-state XML without disabling DTD processing, allowing unauthenticated denial of service via recursive XML entity expansion.Show less

IBM Engineering Lifecycle Management 7.0.3 ( Interim Fix 001 through ) Interim Fix 021, 7.1.0 ( Interim Fix 001 through ) Interim Fix 009, and 7.2.0 and 7.2.0 Interim Fix 001 DOORS could allow a remote attacker to cause a denial of service due to improper handling of XML entity expansion.Show less

Symfony is a PHP framework for web and console applications and a set of reusable PHP components. Prior to 5.4.52, 6.4.40, 7.4.12, and 8.0.12, Symfony\Component\Yaml\Parser resolved YAML collection aliases recursively, allowing a small untrusted YAML input to expand into a multi-gigabyte structure and exhaust memory. This issue is fixed in versions 5.4.52, 6.4.40, 7.4.12, and 8.0.12.Show less

Symfony is a PHP framework for web and console applications and a set of reusable PHP components. Prior to 5.4.52, 6.4.40, 7.4.12, and 8.0.12, when the parser is exposed to attacker-controlled input, deeply nested mappings or sequences cause both the block-level (Parser::parseBlock()) and inline (Inline::parseSequence() / Inline::parseMapping()) parsers to recurse without a depth limit. A crafted document exhausts the PHP stack and crashes the worker. This issue is fixed in versions 5.4.52, 6.4.40, 7.4.12, and 8.0.12.Show less

Docling simplifies document processing by parsing diverse formats and providing integrations with the generative AI ecosystem. From 2.45.0 until 2.91.0, the METS-GBS backend's XML parsing and the input document format detection lacked security controls. An attacker could craft malicious METS-GBS archives that, when processed, could read sensitive files, exhaust system resources, or cause application crashes. This vulnerability is fixed in 2.91.0.Show less