CVE-2026-6879
lowpriority · track · 0EPSS 0.004 · 29 %ileEUFRUSEPSS · scored 2026-10-28
`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.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (21)
Products and version ranges known to be affected.
advisories (5)
Vendor and ecosystem advisories describing this.
- BIT-libpython-2026-6879Quadratic Behavior in xml.etree.ElementPath Index Predicates2026-08-17vendor · osvUS
`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.
- BIT-python-2026-6879Quadratic Behavior in xml.etree.ElementPath Index Predicates2026-08-17vendor · osvUS
`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.
- BIT-python-min-2026-6879Quadratic Behavior in xml.etree.ElementPath Index Predicates2026-08-17vendor · osvUS
`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.
- CERTFR-2026-AVI-1385Multiples vulnérabilités dans les produits VMwareFrançais2026-10-26vendor · certfrFR
- PSF-2026-342026-07-28vendor · osvUS
`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.
also known as (7)
Other names and identifiers for this entity.
- CNNVD-2026-38913134cnnvd
- EUVD-2026-49850enisa_euvd
- GHSA-77qw-3xm6-r2ppenisa_euvd
- BIT-libpython-2026-6879osv
- BIT-python-2026-6879osv
- BIT-python-min-2026-6879osv
- PSF-2026-34osv
sources
Which sources assert this record, and when.
references (25)
External citations — patches, advisories, analysis.
- https://github.com/python/cpython/commit/2ffab083782968a4d732738f4f1dff6bbd69d2b0cnnvd
- https://github.com/python/cpython/issues/152674cnnvd
- https://github.com/python/cpython/pull/152676cnnvd
- https://mail.python.org/archives/list/security-announce@python.org/thread/7YMZ6DDZVR26TJJBVO3RDNBAVGHNYAKR/cnnvd
- https://www.python.org/Patchcnnvd
- https://github.com/python/cpython/commit/02c08e6b747ac43d0d866a4ffa916bedf3423f81enisa_euvd
- https://github.com/python/cpython/commit/037965c00a427cba5c05447efadc67c51a492e85enisa_euvd
- https://github.com/python/cpython/commit/0583f24ae678993e3f7939f51ad5bcae5ad9dc70enisa_euvd
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