CVE-2022-25236 — CVSS 9.8 (critical): xmlparse.c in Expat (aka libexpat) before 2.4.5 allows attackers to insert namespace-separator characters into namespace URIs.
CVE-2022-25235 — CVSS 9.8 (critical): xmltok_impl.c in Expat (aka libexpat) before 2.4.5 lacks certain validation of encoding, such as checks for whether a UTF-8 character is…
CVE-2022-23852 — CVSS 9.8 (critical): Expat (aka libexpat) before 2.4.4 has a signed integer overflow in XML_GetBuffer, for configurations with a nonzero XML_CONTEXT_BYTES.
CVE-2016-0718 — CVSS 9.8 (critical): Expat allows context-dependent attackers to cause a denial of service (crash) or possibly execute arbitrary code via a malformed input…
CVE-2024-45492 — CVSS 9.8 (critical): An issue was discovered in libexpat before 2.6.3. nextScaffoldPart in xmlparse.c can have an integer overflow for m_groupSize on 32-bit…
CVE-2024-45491 — CVSS 9.8 (critical): An issue was discovered in libexpat before 2.6.3. dtdCopy in xmlparse.c can have an integer overflow for nDefaultAtts on 32-bit platforms…
CVE-2021-45960 — CVSS 8.8 (high): In Expat (aka libexpat) before 2.4.3, a left shift by 29 (or more) places in the storeAtts function in xmlparse.c can lead to realloc…
CVE-2016-4472 — CVSS 8.1 (high): The overflow protection in Expat is removed by compilers with certain optimization settings, which allows remote attackers to cause a…
CVE-2021-46143 — CVSS 8.1 (high): In doProlog in xmlparse.c in Expat (aka libexpat) before 2.4.3, an integer overflow exists for m_groupSize.
CVE-2017-11742 — CVSS 7.8 (high): The writeRandomBytes_RtlGenRandom function in xmlparse.c in libexpat in Expat 2.2.1 and 2.2.2 on Windows allows local users to gain…
CVE-2025-59375 — CVSS 7.5 (high): libexpat in Expat before 2.7.2 allows attackers to trigger large dynamic memory allocations via a small document that is submitted for…
CVE-2016-5300 — CVSS 7.5 (high): The XML parser in Expat does not use sufficient entropy for hash initialization, which allows context-dependent attackers to cause a denial…
CVE-2017-9233 — CVSS 7.5 (high): XML External Entity vulnerability in libexpat 2.2.0 and earlier (Expat XML Parser Library) allows attackers to put the parser in an…
CVE-2018-20843 — CVSS 7.5 (high): In libexpat in Expat before 2.2.7, XML input including XML names that contain a large number of colons could make the XML parser consume a…
CVE-2019-15903 — CVSS 7.5 (high): In libexpat before 2.2.8, crafted XML input could fool the parser into changing from DTD parsing to document parsing too early; a…
CVE-2022-43680 — CVSS 7.5 (high): In libexpat through 2.4.9, there is a use-after free caused by overeager destruction of a shared DTD in XML_ExternalEntityParserCreate in…
CVE-2023-52425 — CVSS 7.5 (high): libexpat through 2.5.0 allows a denial of service (resource consumption) because many full reparsings are required in the case of a large…
CVE-2024-28757 — CVSS 7.5 (high): libexpat through 2.6.1 allows an XML Entity Expansion attack when there is isolated use of external parsers (created via…
CVE-2024-45490 — CVSS 7.5 (high): An issue was discovered in libexpat before 2.6.3. xmlparse.c does not reject a negative length for XML_ParseBuffer.
CVE-2026-56407 — CVSS 6.9 (medium): libexpat before 2.8.2 has an integer overflow in doProlog that is related to storeEntityValue and entity textLen.
CVE-2026-56132 — CVSS 6.9 (medium): In libexpat before 2.8.2, there is a heap-based buffer overflow in doProlog in xmlparse.c because scaffold backing array reallocation is…
CVE-2026-56406 — CVSS 6.9 (medium): libexpat before 2.8.2 has an integer overflow in XML_ParseBuffer because it lacked a check that was present in XML_Parse.
CVE-2026-25210 — CVSS 6.9 (medium): In libexpat before 2.7.4, the doContent function does not properly determine the buffer size bufSize because there is no integer overflow…
CVE-2015-1283 — CVSS 6.8 (medium): Multiple integer overflows in the XML_GetBuffer function in Expat through 2.1.0, as used in Google Chrome before 44.0.2403.89 and other…
CVE-2013-0340 — CVSS 6.8 (medium): expat before version 2.4.0 does not properly handle entities expansion unless an application developer uses the XML_SetEntityDeclHandler…
CVE-2022-25313 — CVSS 6.5 (medium): In Expat (aka libexpat) before 2.4.5, an attacker can trigger stack exhaustion in build_model via a large nesting depth in the DTD element.
CVE-2026-56409 — CVSS 6.5 (medium): xmlwf in libexpat before 2.8.2 has an integer overflow for the output filename when -d outputDir is used.
CVE-2012-6702 — CVSS 5.9 (medium): Expat, when used in a parser that has not called XML_SetHashSalt or passed it a seed of 0, makes it easier for context-dependent attackers…
CVE-2024-50602 — CVSS 5.9 (medium): An issue was discovered in libexpat before 2.6.4. There is a crash within the XML_ResumeParser function because XML_StopParser can…
CVE-2023-52426 — CVSS 5.5 (medium): libexpat through 2.5.0 allows recursive XML Entity Expansion if XML_DTD is undefined at compile time.
CVE-2012-1148 — CVSS 5.0 (medium): Memory leak in the poolGrow function in expat/lib/xmlparse.c in expat before 2.1.0 allows context-dependent attackers to cause a denial of…
CVE-2009-3560 — CVSS 5.0 (medium): The big2_toUtf8 function in lib/xmltok.c in libexpat in Expat 2.0.1, as used in the XML-Twig module for Perl, allows context-dependent…
CVE-2009-3720 — CVSS 5.0 (medium): The updatePosition function in lib/xmltok_impl.c in libexpat in Expat 2.0.1, as used in Python, PyXML, w3c-libwww, and other software…
CVE-2026-56412 — CVSS 4.9 (medium): libexpat before 2.8.2 does not consider XML_TOK_DATA_CHARS in doCdataSection and thus lacks handler call depth tracking for various calls…
CVE-2026-50219 — CVSS 4.9 (medium): libexpat before 2.8.2 lacks handler call depth tracking for calls to XML_GetBuffer, XML_Parse, XML_ParseBuffer, XML_ParserFree, or…
CVE-2026-56131 — CVSS 4.9 (medium): libexpat before 2.8.2 lacks handler call depth tracking for calls to XML_ResumeParser from within handlers in cases of a policy violation…
CVE-2012-0876 — CVSS 4.3 (medium): The XML parser (xmlparse.c) in expat before 2.1.0 computes hash values without restricting the ability to trigger hash collisions…
CVE-2012-1147 — CVSS 4.3 (medium): readfilemap.c in expat before 2.1.0 allows context-dependent attackers to cause a denial of service (file descriptor consumption) via a…
CVE-2026-32776 — CVSS 4.0 (medium): libexpat before 2.7.5 allows a NULL pointer dereference with empty external parameter entity content.
CVE-2026-45186 — CVSS 2.9 (low): In libexpat before 2.8.1, the computational complexity of attribute name collision checks allows a denial of service via moderately sized…
CVE-2026-24515 — CVSS 2.9 (low): In libexpat before 2.7.4, XML_ExternalEntityParserCreate does not copy unknown encoding handler user data.
CVE-2026-41080 — CVSS 2.9 (low): libexpat before 2.8.0 uses insufficient entropy, and thus hash flooding can occur via a crafted XML document.
CVE-2026-32778 — CVSS 2.9 (low): libexpat before 2.7.5 allows a NULL pointer dereference in the function setContext on retry after an earlier ouf-of-memory condition.
CVE-2025-66382 — CVSS 2.9 (low): In libexpat through 2.7.3, a crafted file with an approximate size of 2 MiB can lead to dozens of seconds of processing time.