Priority LOW 36
libexpat through 2.9.0 contains a signed integer overflow vulnerability in storeAtts() in lib/xmlparse.c that allows attackers to trigger out-of-bounds writes via oversized attribute counts.
CVSS 4.0HIGH 8.2· Network · No auth · No interaction · EPSS 0.00391 · Published 2026-10-28 · No fix listed CWE-190
Priority LOW 36
libexpat through 2.9.0 contains a NULL pointer dereference vulnerability in externalEntityInitProcessor2() in lib/xmlparse.c that mishandles the XML_TOK_NONE token from empty input.
CVSS 4.0HIGH 8.2· Network · No auth · No interaction · EPSS 0.00425 · Published 2026-10-28 · No fix listed CWE-476
Priority HIGH 77
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.
CVSS 4.0HIGH 8.7· Network · No auth · No interaction · EPSS 0.00448 · Published 2026-10-22 · No fix listed CWE-776
Priority LOW 36
libexpat 2.7.2 through 2.9.0 contains a denial of service vulnerability because XML_ParserReset zeroes the direct byte count but never offsets tracked heap allocations.
CVSS 4.0HIGH 8.2· Network · No auth · No interaction · EPSS 0.00494 · Published 2026-10-20 · Partial fix CWE-909
Priority LOW 33
libexpat before 2.8.4 lacks handler call depth tracking with custom encoding callbacks.
CVSS 3.1HIGH 7.8· Local · Low privileges · No interaction · EPSS 0.00107 · Published 2026-08-20 · Partial fix · 2.8.4 CWE-416
Priority LOW 39
In libexpat 2.8.2 and 2.8.3 before 2.8.4, misinterpretation of getentropy's return code leads to insufficient entropy, which results in being vulnerable to hash flooding attacks, causing a denial of service via crafted X…
CVSS 3.1HIGH 7.5· Network · No auth · No interaction · EPSS 0.00287 · Published 2026-08-20 · Fixed in 2.8.4 CWE-394
Priority MEDIUM 45
Expat 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 trig…
CVSS 4.0HIGH 8.7· Network · No auth · No interaction · EPSS 0.00742 · Published 2026-08-18 · Partial fix CWE-407
Priority LOW 26
libexpat before 2.8.2 does not consider XML_TOK_DATA_CHARS in doCdataSection and thus lacks handler call depth tracking for various calls from within handlers in cases of a policy violation.
CVSS 3.1MEDIUM 5.9· Local · No auth · No interaction · EPSS 0.00179 · Published 2026-06-21 · Partial fix · 2.8.2 CWE-416
Priority LOW 31
xmlwf in libexpat before 2.8.2 has an integer overflow in endDoctypeDecl via NOTATION declarations.
CVSS 3.1MEDIUM 6.9· Local · No auth · No interaction · EPSS 0.00129 · Published 2026-06-21 · Partial fix · 2.8.2 CWE-190
Priority LOW 31
xmlwf in libexpat before 2.8.2 has an integer overflow in resolveSystemId.
CVSS 3.1MEDIUM 6.9· Local · No auth · No interaction · EPSS 0.00129 · Published 2026-06-21 · Partial fix · 2.8.2 CWE-190
Priority LOW 30
xmlwf in libexpat before 2.8.2 has an integer overflow for the output filename when -d outputDir is used.
CVSS 3.1MEDIUM 6.5· Local · No auth · User interaction · EPSS 0.00119 · Published 2026-06-21 · Partial fix · 2.8.2 CWE-190
Priority LOW 31
libexpat before 2.8.2 has an integer overflow in copyString.
CVSS 3.1MEDIUM 6.9· Local · No auth · No interaction · EPSS 0.00125 · Published 2026-06-21 · Partial fix · 2.8.2 CWE-190
Priority LOW 32
libexpat before 2.8.2 has an integer overflow in doProlog that is related to storeEntityValue and entity textLen.
CVSS 3.1MEDIUM 6.9· Local · No auth · No interaction · EPSS 0.00174 · Published 2026-06-21 · Partial fix · 2.8.2 CWE-190
Priority LOW 32
libexpat before 2.8.2 has an integer overflow in XML_ParseBuffer because it lacked a check that was present in XML_Parse.
CVSS 3.1MEDIUM 6.9· Local · No auth · No interaction · EPSS 0.00174 · Published 2026-06-21 · Partial fix · 2.8.2 CWE-190
Priority LOW 31
libexpat before 2.8.2 has an integer overflow in getAttributeId.
CVSS 3.1MEDIUM 6.9· Local · No auth · No interaction · EPSS 0.00125 · Published 2026-06-21 · Partial fix · 2.8.2 CWE-190
Priority LOW 31
libexpat before 2.8.2 has an integer overflow in addBinding.
CVSS 3.1MEDIUM 6.9· Local · No auth · No interaction · EPSS 0.0013 · Published 2026-06-21 · Partial fix · 2.8.2 CWE-190
Priority LOW 32
libexpat before 2.8.2 has an integer overflow in storeAtts.
CVSS 3.1MEDIUM 6.9· Local · No auth · No interaction · EPSS 0.00168 · Published 2026-06-21 · Partial fix · 2.8.2 CWE-190
Priority LOW 31
In libexpat before 2.8.2, there is a heap-based buffer overflow in doProlog in xmlparse.c because scaffold backing array reallocation is mishandled when there is data-structure sharing across parsers.
CVSS 3.1MEDIUM 6.9· Local · No auth · No interaction · EPSS 0.00135 · Published 2026-06-19 · Partial fix · 2.8.2 CWE-821
Priority LOW 22
libexpat before 2.8.2 lacks handler call depth tracking for calls to XML_ResumeParser from within handlers in cases of a policy violation.
CVSS 3.1MEDIUM 4.9· Local · No auth · No interaction · EPSS 0.00175 · Published 2026-06-19 · Partial fix · 2.8.2 CWE-416
Priority LOW 26
libexpat before 2.8.2 lacks handler call depth tracking for calls to XML_GetBuffer, XML_Parse, XML_ParseBuffer, XML_ParserFree, or XML_ParserReset from within handlers in cases of a policy violation.
CVSS 3.1MEDIUM 5.9· Local · No auth · No interaction · EPSS 0.00181 · Published 2026-06-04 · Partial fix · 2.8.2 CWE-416
Priority LOW 33
In libexpat before 2.8.1, the computational complexity of attribute name collision checks allows a denial of service via moderately sized crafted XML input.
CVSS 3.1HIGH 7.5· Network · No auth · No interaction · EPSS 0.00479 · Published 2026-05-10 · Partial fix · 2.8.1 CWE-407
Priority LOW 33
libexpat before 2.8.0 uses insufficient entropy, and thus hash flooding can occur via a crafted XML document.
CVSS 3.1HIGH 7.5· Network · No auth · No interaction · EPSS 0.00398 · Published 2026-04-16 · Partial fix · 2.8.0 CWE-331
Priority LOW 24
libexpat before 2.7.5 allows a NULL pointer dereference in the function setContext on retry after an earlier ouf-of-memory condition.
CVSS 3.1MEDIUM 5.5· Local · Low privileges · No interaction · EPSS 0.00177 · Published 2026-03-16 · Partial fix · 2.7.5 CWE-476
Priority LOW 24
libexpat before 2.7.5 allows an infinite loop while parsing DTD content.
CVSS 3.1MEDIUM 5.5· Local · Low privileges · No interaction · EPSS 0.00225 · Published 2026-03-16 · Partial fix · 2.7.5 CWE-835
Priority LOW 24
libexpat before 2.7.5 allows a NULL pointer dereference with empty external parameter entity content.
CVSS 3.1MEDIUM 5.5· Local · Low privileges · No interaction · EPSS 0.00171 · Published 2026-03-16 · Partial fix · 2.7.5 CWE-476
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