| Name | CVE-2026-6879 |
| 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. |
| Source | CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more) |
The table below lists information on source packages.
| Source Package | Release | Version | Status |
|---|---|---|---|
| pypy3 (PTS) | bullseye | 7.3.5+dfsg-2+deb11u2 | vulnerable |
| bullseye (security) | 7.3.5+dfsg-2+deb11u5 | vulnerable | |
| bookworm | 7.3.11+dfsg-2+deb12u3 | vulnerable | |
| trixie | 7.3.19+dfsg-2 | vulnerable | |
| forky, sid | 7.3.23+dfsg-1 | vulnerable | |
| python2.7 (PTS) | bullseye | 2.7.18-8+deb11u1 | vulnerable |
| python3.11 (PTS) | bookworm | 3.11.2-6+deb12u8 | vulnerable |
| bookworm (security) | 3.11.2-6+deb12u3 | vulnerable | |
| python3.13 (PTS) | trixie | 3.13.5-2+deb13u3 | vulnerable |
| forky | 3.13.14-1 | vulnerable | |
| sid | 3.13.15-1 | fixed | |
| python3.14 (PTS) | forky | 3.14.6-1 | vulnerable |
| sid | 3.14.7-1 | fixed | |
| python3.9 (PTS) | bullseye | 3.9.2-1 | vulnerable |
| bullseye (security) | 3.9.2-1+deb11u7 | vulnerable |
The information below is based on the following data on fixed versions.
| Package | Type | Release | Fixed Version | Urgency | Origin | Debian Bugs |
|---|---|---|---|---|---|---|
| pypy3 | source | (unstable) | (unfixed) | |||
| python2.7 | source | bullseye | (unfixed) | end-of-life | ||
| python2.7 | source | (unstable) | (unfixed) | |||
| python3.11 | source | (unstable) | (unfixed) | |||
| python3.13 | source | (unstable) | 3.13.15-1 | |||
| python3.14 | source | (unstable) | 3.14.7-1 | |||
| python3.9 | source | (unstable) | (unfixed) |
[trixie] - python3.13 <no-dsa> (Minor issue)
[bookworm] - python3.11 <postponed> (Minor issue)
[bullseye] - python3.9 <postponed> (Minor issue)
[bullseye] - python2.7 <end-of-life> (EOL in bullseye LTS)
[trixie] - pypy3 <no-dsa> (Minor issue)
[bookworm] - pypy3 <postponed> (Minor issue)
[bullseye] - pypy3 <postponed> (Minor issue)
https://mail.python.org/archives/list/security-announce@python.org/thread/7YMZ6DDZVR26TJJBVO3RDNBAVGHNYAKR/
https://github.com/python/cpython/issues/152674
https://github.com/python/cpython/pull/152676
https://github.com/python/cpython/commit/2ffab083782968a4d732738f4f1dff6bbd69d2b0 (main)
https://github.com/python/cpython/commit/cb409342a19f25656f62e679f8bac265fe1442c3 (v3.14.7)
https://github.com/python/cpython/commit/390337b8ba1658833fdef379e1739c9f9533a8db (v3.13.15)
https://github.com/python/cpython/commit/0583f24ae678993e3f7939f51ad5bcae5ad9dc70 (v3.11.16)