Back
CVE-2026-6879
Quadratic Behavior in xml.etree.ElementPath Index Predicates
Low2.0EPSS 0.36%
- Published
- Updated
- Reserved
- Assigned by
- PSF
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.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| PSFCNA (assigner) | 4.0 | Low2.0 | CVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N |
| NVDNVD · Awaiting Analysis | 4.0 | Low2.0 | CVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
- EPSS (exploitation in 30 days)
- 0.36% · top 71% of all CVEs (6 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
Loading the EPSS history…
The list uses the assigner's score when there is one, then CISA's, then NVD's: Low 2.0.
Weakness
Affected products
Python Software Foundation · CPython
- affected < 3.10.21
- affected 3.11.0 – < 3.11.16
- affected 3.12.0 – < 3.12.14
- affected 3.13.0 – < 3.13.15
- affected 3.14.0 – < 3.14.7
- affected 3.15.0a1 – < 3.15.0rc1
References (10)
- https://github.com/python/cpython/pull/152676 (opens in a new tab)patch
- https://github.com/python/cpython/issues/152674 (opens in a new tab)issue-tracking
- https://mail.python.org/archives/list/[email protected]/thread/7YMZ6DDZVR26TJJBVO3RDNBAVGHNYAKR/ (opens in a new tab)vendor-advisory
- https://github.com/python/cpython/commit/2ffab083782968a4d732738f4f1dff6bbd69d2b0 (opens in a new tab)patch
- https://github.com/python/cpython/commit/02c08e6b747ac43d0d866a4ffa916bedf3423f81 (opens in a new tab)patch
- https://github.com/python/cpython/commit/390337b8ba1658833fdef379e1739c9f9533a8db (opens in a new tab)patch
- https://github.com/python/cpython/commit/cb409342a19f25656f62e679f8bac265fe1442c3 (opens in a new tab)patch
- https://github.com/python/cpython/commit/96510a3758f4a075f43223afdee3b6ee1a7a7f02 (opens in a new tab)patch
- https://github.com/python/cpython/commit/037965c00a427cba5c05447efadc67c51a492e85 (opens in a new tab)patch
- https://github.com/python/cpython/commit/0583f24ae678993e3f7939f51ad5bcae5ad9dc70 (opens in a new tab)patch
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2026-6879)Record last updated .