CVE-2026-6879

Summary

Element.findall() and fully-consumed Element.iterfind() exhibit O(n^2) time complexity when using XPath index predicates (e.g. [1], [last()], [last()-N]) on XML documents with many same-tag siblings. Element.find() is only affected when the first match is near the end  of the sibling list, such as with [last()] or [last()-N].//item[1] short-circuits after the first match.

Affected Software

VendorProductVersion RangeStatus
Python Software FoundationCPython0 < 3.15.0affected

Weaknesses

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: partial

References