CVE-2026-6879 | BDVDB-2026-353133 Detail
Python Software FoundationCPython
Description#
`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.
Impact#
Per CVSS v4.0: confidentiality impact none, integrity impact none, availability impact low. Attack vector: network.
Weaknesses#
- CWE-407 Inefficient Algorithmic Complexity
References#
- https://github.com/python/cpython/pull/152676
- https://github.com/python/cpython/issues/152674
- https://mail.python.org/archives/list/security-announce@python.org/thread/7YMZ6DDZVR26TJJBVO3RDNBAVGHNYAKR/
- https://github.com/python/cpython/commit/2ffab083782968a4d732738f4f1dff6bbd69d2b0
- https://github.com/python/cpython/commit/02c08e6b747ac43d0d866a4ffa916bedf3423f81
- https://github.com/python/cpython/commit/390337b8ba1658833fdef379e1739c9f9533a8db
- https://github.com/python/cpython/commit/cb409342a19f25656f62e679f8bac265fe1442c3
- https://github.com/python/cpython/commit/96510a3758f4a075f43223afdee3b6ee1a7a7f02
- https://github.com/python/cpython/commit/037965c00a427cba5c05447efadc67c51a492e85
- https://github.com/python/cpython/commit/0583f24ae678993e3f7939f51ad5bcae5ad9dc70
Exploit#
No public exploit known
History#
- Version 1Record published in the CVE List.
- Version 2Most recent update recorded in the CVE List.