CVE-2013-0340Medium· 6.8▾ Sunlitexpat before version 2.4.0 does not properly handle entities expansion unless an application developer uses the XML_SetEntityDeclHandler function, which allows remote attackers to cause a denial of service (resource consumption), send HT…
▾ Sunlit zone — Low / medium · no exploitation signal
impact 37.4 · likelihood 3.9 · exploitation 0
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Disclosure to exploitation, from the record and what we observed since indexing it.
Disclosed via NVD
Last analysed / modified upstream
19%
expat before version 2.4.0 does not properly handle entities expansion unless an application developer uses the XML_SetEntityDeclHandler function, which allows remote attackers to cause a denial of service (resource consumption), send HTTP requests to intranet servers, or read arbitrary files via a crafted XML document, aka an XML External Entity (XXE) issue. NOTE: it could be argued that because expat already provides the ability to disable external entity expansion, the responsibility for resolving this issue lies with application developers; according to this argument, this entry should be REJECTed, and each affected application would need its own CVE.
libexpat < 2.4.0python >= 3.6.0, < 3.6.15python >= 3.7.0, < 3.7.12python >= 3.8.0, < 3.8.12python >= 3.9.0, < 3.9.7ipados < 14.8iphone_os < 14.8macos < 11.6tvos < 15.0watchos < 8.0Upgrade past the affected range:
libexpat 2.4.0python 3.9.7ipados 14.8iphone_os 14.8macos 11.6tvos 15.0watchos 8.0Connected by shared product, vendor, weakness, or advisory.
CVE-2016-4472High· 8.1The overflow protection in Expat is removed by compilers with certain optimization settings, which allows remote attackers to cause a denial of service (crash) or possibly execute arbitrary code via crafted XML data
CVE-2017-9233High· 7.5XML External Entity vulnerability in libexpat 2.2.0 and earlier (Expat XML Parser Library) allows attackers to put the parser in an infinite loop using a malformed external entity definition from an external DTD.
CVE-2026-77214High· 8.2libexpat before commit 13c5f63 contains a heap buffer over-read vulnerability in xmlparse.c
CVE-2026-102633Medium· 5.9libexpat versions 2.7.2 through 2.8.5 contain an integer overflow vulnerability in expat_realloc() function on 32-bit platforms when computing allocation sizes
CVE-2026-93990High· 7.5Expat before 2.8.5 fails to validate that a high surrogate in UTF-16 input is followed by a low surrogate, allowing malformed UTF-16 sequences to be accepted
CVE-2026-66046High· 7.5Expat through 2.8.3 contains a denial of service vulnerability caused by quadratic algorithmic complexity in the storeAtts() function in xmlparse.c, where processing N specified attributes with non-normalized values triggers an O(N^2) li…