In xmlIO in libxml2 before 2.15.4, an inconsistency in xmlOutputWriteCallback and xmlBufUse causes negative lengths to reach write callbacks, aka a lack of a check for integer overflow before calling writecallback. This has security relevance for many types of uses of that length value within a callback.
{
"cna_assigner": "mitre",
"cwe_ids": [
"CWE-192"
],
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/86xxx/CVE-2026-86143.json"
}{
"extracted_events": [
{
"cpe": "cpe:2.3:a:xmlsoft:libxml2:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "0"
},
{
"fixed": "2.15.4"
}
],
"source": "CPE_RANGE"
},
{
"range": [
{
"fixed": "90f293ba74d28b1d570920382e707586f68ebf35"
}
],
"source": "REFERENCES_COMMIT"
}
]
}
{
"extracted_events": [
{
"cpe": "cpe:2.3:a:xmlsoft:libxml2:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "0"
},
{
"fixed": "2.15.4"
}
],
"source": "CPE_RANGE"
}
]
}