numbers.c in libxslt before 1.1.43 has a use-after-free because, in nested XPath evaluations, an XPath context node can be modified but never restored. This is related to xsltNumberFormatGetValue, xsltEvalXPathPredicate, xsltEvalXPathStringNs, and xsltComputeSortResultInternal.
Exploitability
AV:LAC:HPR:NUI:NScope
S:CImpact
C:NI:HA:H7.8/CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:C/C:N/I:H/A:HMemory Safety