# CVE-2026-6879: Quadratic Behavior in xml.etree.ElementPath Index Predicates

CVE-2026-6879 is fixed in 54 products on 3 platforms, first by DEBIAN-CVE-2026-6879, released July 28, 2026. 10 other affected products have no fix yet. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-6879
- Priority: Routine
- CVSS: 2.0 (low)
- EPSS: 0.0036
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Jul 28, 2026
- Weakness: CWE-407: Inefficient Algorithmic Complexity
- Vendor advisory: https://nvd.nist.gov/vuln/detail/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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Windows apps | Python 3.13 | 3.13.15 | [Python 3.13 3.13.15](https://patchblox.com/security/data/fix/windows-app/python.python.3.13-3.13.15.md) | Aug 5, 2026 |
| Windows apps | Python 3.14 | 3.14.7 | [Python 3.14 3.14.7](https://patchblox.com/security/data/fix/windows-app/python.python.3.14-3.14.7.md) | Aug 5, 2026 |
| Linux | pypy3 Debian 14 | 8.0.0+dfsg-1 | [DEBIAN-CVE-2026-6879](https://patchblox.com/security/data/fix/linux/debian-cve-2026-6879.md) | Jul 28, 2026 |
| Linux | python sles 15.7 | 2.7.18-150000.133.1 | [SUSE-SU-2026:4411-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4411-1.md) | Oct 1, 2026 |
| Linux | python-base sles 15.7 | 2.7.18-150000.133.1 | [SUSE-SU-2026:4411-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4411-1.md) | Oct 1, 2026 |
| Linux | python3 sles 15.6 | 3.6.15-150300.10.129.1 | [SUSE-SU-2026:4754-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4754-1.md) | Nov 7, 2026 |
| Linux | python3 sles 15.7 | 3.6.15-150300.10.129.1 | [SUSE-SU-2026:4754-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4754-1.md) | Nov 7, 2026 |
| Linux | python3-core sles 15.6 | 3.6.15-150300.10.129.1 | [SUSE-SU-2026:4754-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4754-1.md) | Nov 7, 2026 |
| Linux | python3-core sles 15.7 | 3.6.15-150300.10.129.1 | [SUSE-SU-2026:4754-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4754-1.md) | Nov 7, 2026 |
| Linux | python3.11 amzn 2023 | 3.11.16-1.amzn2023.0.1 | [ALAS2023-2026-2125](https://patchblox.com/security/data/fix/linux/alas2023-2026-2125.md) | Aug 31, 2026 |
| Linux | python3.11-debug amzn 2023 | 3.11.16-1.amzn2023.0.1 | [ALAS2023-2026-2125](https://patchblox.com/security/data/fix/linux/alas2023-2026-2125.md) | Aug 31, 2026 |
| Linux | python3.11-debuginfo amzn 2023 | 3.11.16-1.amzn2023.0.1 | [ALAS2023-2026-2125](https://patchblox.com/security/data/fix/linux/alas2023-2026-2125.md) | Aug 31, 2026 |
| Linux | python3.11-debugsource amzn 2023 | 3.11.16-1.amzn2023.0.1 | [ALAS2023-2026-2125](https://patchblox.com/security/data/fix/linux/alas2023-2026-2125.md) | Aug 31, 2026 |
| Linux | python3.11-devel amzn 2023 | 3.11.16-1.amzn2023.0.1 | [ALAS2023-2026-2125](https://patchblox.com/security/data/fix/linux/alas2023-2026-2125.md) | Aug 31, 2026 |
| Linux | python3.11-idle amzn 2023 | 3.11.16-1.amzn2023.0.1 | [ALAS2023-2026-2125](https://patchblox.com/security/data/fix/linux/alas2023-2026-2125.md) | Aug 31, 2026 |
| Linux | python3.11-libs amzn 2023 | 3.11.16-1.amzn2023.0.1 | [ALAS2023-2026-2125](https://patchblox.com/security/data/fix/linux/alas2023-2026-2125.md) | Aug 31, 2026 |
| Linux | python3.11-test amzn 2023 | 3.11.16-1.amzn2023.0.1 | [ALAS2023-2026-2125](https://patchblox.com/security/data/fix/linux/alas2023-2026-2125.md) | Aug 31, 2026 |
| Linux | python3.11-tkinter amzn 2023 | 3.11.16-1.amzn2023.0.1 | [ALAS2023-2026-2125](https://patchblox.com/security/data/fix/linux/alas2023-2026-2125.md) | Aug 31, 2026 |
| Linux | python3.12 amzn 2023 | 3.12.14-2.amzn2023.0.1 | [ALAS2023-2026-2124](https://patchblox.com/security/data/fix/linux/alas2023-2026-2124.md) | Aug 31, 2026 |
| Linux | python3.12-debug amzn 2023 | 3.12.14-2.amzn2023.0.1 | [ALAS2023-2026-2124](https://patchblox.com/security/data/fix/linux/alas2023-2026-2124.md) | Aug 31, 2026 |
| Linux | python3.12-debuginfo amzn 2023 | 3.12.14-2.amzn2023.0.1 | [ALAS2023-2026-2124](https://patchblox.com/security/data/fix/linux/alas2023-2026-2124.md) | Aug 31, 2026 |
| Linux | python3.12-debugsource amzn 2023 | 3.12.14-2.amzn2023.0.1 | [ALAS2023-2026-2124](https://patchblox.com/security/data/fix/linux/alas2023-2026-2124.md) | Aug 31, 2026 |
| Linux | python3.12-devel amzn 2023 | 3.12.14-2.amzn2023.0.1 | [ALAS2023-2026-2124](https://patchblox.com/security/data/fix/linux/alas2023-2026-2124.md) | Aug 31, 2026 |
| Linux | python3.12-idle amzn 2023 | 3.12.14-2.amzn2023.0.1 | [ALAS2023-2026-2124](https://patchblox.com/security/data/fix/linux/alas2023-2026-2124.md) | Aug 31, 2026 |
| Linux | python3.12-libs amzn 2023 | 3.12.14-2.amzn2023.0.1 | [ALAS2023-2026-2124](https://patchblox.com/security/data/fix/linux/alas2023-2026-2124.md) | Aug 31, 2026 |
| Linux | python3.12-test amzn 2023 | 3.12.14-2.amzn2023.0.1 | [ALAS2023-2026-2124](https://patchblox.com/security/data/fix/linux/alas2023-2026-2124.md) | Aug 31, 2026 |
| Linux | python3.12-tkinter amzn 2023 | 3.12.14-2.amzn2023.0.1 | [ALAS2023-2026-2124](https://patchblox.com/security/data/fix/linux/alas2023-2026-2124.md) | Aug 31, 2026 |
| Linux | python3.13 Debian 13.5 (trixie) | 3.13.5-2+deb13u5 | [DEBIAN-CVE-2026-6879](https://patchblox.com/security/data/fix/linux/debian-cve-2026-6879.md) | Jul 28, 2026 |
| Linux | python3.13 amzn 2023 | 3.13.15-1.amzn2023.0.1 | [ALAS2023-2026-2123](https://patchblox.com/security/data/fix/linux/alas2023-2026-2123.md) | Aug 31, 2026 |
| Linux | python3.13-debug amzn 2023 | 3.13.15-1.amzn2023.0.1 | [ALAS2023-2026-2123](https://patchblox.com/security/data/fix/linux/alas2023-2026-2123.md) | Aug 31, 2026 |
| Linux | python3.13-debuginfo amzn 2023 | 3.13.15-1.amzn2023.0.1 | [ALAS2023-2026-2123](https://patchblox.com/security/data/fix/linux/alas2023-2026-2123.md) | Aug 31, 2026 |
| Linux | python3.13-debugsource amzn 2023 | 3.13.15-1.amzn2023.0.1 | [ALAS2023-2026-2123](https://patchblox.com/security/data/fix/linux/alas2023-2026-2123.md) | Aug 31, 2026 |
| Linux | python3.13-devel amzn 2023 | 3.13.15-1.amzn2023.0.1 | [ALAS2023-2026-2123](https://patchblox.com/security/data/fix/linux/alas2023-2026-2123.md) | Aug 31, 2026 |
| Linux | python3.13-freethreading amzn 2023 | 3.13.15-1.amzn2023.0.1 | [ALAS2023-2026-2123](https://patchblox.com/security/data/fix/linux/alas2023-2026-2123.md) | Aug 31, 2026 |
| Linux | python3.13-freethreading-debug amzn 2023 | 3.13.15-1.amzn2023.0.1 | [ALAS2023-2026-2123](https://patchblox.com/security/data/fix/linux/alas2023-2026-2123.md) | Aug 31, 2026 |
| Linux | python3.13-idle amzn 2023 | 3.13.15-1.amzn2023.0.1 | [ALAS2023-2026-2123](https://patchblox.com/security/data/fix/linux/alas2023-2026-2123.md) | Aug 31, 2026 |
| Linux | python3.13-libs amzn 2023 | 3.13.15-1.amzn2023.0.1 | [ALAS2023-2026-2123](https://patchblox.com/security/data/fix/linux/alas2023-2026-2123.md) | Aug 31, 2026 |
| Linux | python3.13-test amzn 2023 | 3.13.15-1.amzn2023.0.1 | [ALAS2023-2026-2123](https://patchblox.com/security/data/fix/linux/alas2023-2026-2123.md) | Aug 31, 2026 |
| Linux | python3.13-tkinter amzn 2023 | 3.13.15-1.amzn2023.0.1 | [ALAS2023-2026-2123](https://patchblox.com/security/data/fix/linux/alas2023-2026-2123.md) | Aug 31, 2026 |
| Linux | python3.14 Debian 14 | 3.14.7-1 | [DEBIAN-CVE-2026-6879](https://patchblox.com/security/data/fix/linux/debian-cve-2026-6879.md) | Jul 28, 2026 |
| Linux | python3.14 amzn 2023 | 3.14.7-1.amzn2023.0.1 | [ALAS2023-2026-2122](https://patchblox.com/security/data/fix/linux/alas2023-2026-2122.md) | Aug 31, 2026 |
| Linux | python3.14-debug amzn 2023 | 3.14.7-1.amzn2023.0.1 | [ALAS2023-2026-2122](https://patchblox.com/security/data/fix/linux/alas2023-2026-2122.md) | Aug 31, 2026 |
| Linux | python3.14-debuginfo amzn 2023 | 3.14.7-1.amzn2023.0.1 | [ALAS2023-2026-2122](https://patchblox.com/security/data/fix/linux/alas2023-2026-2122.md) | Aug 31, 2026 |
| Linux | python3.14-debugsource amzn 2023 | 3.14.7-1.amzn2023.0.1 | [ALAS2023-2026-2122](https://patchblox.com/security/data/fix/linux/alas2023-2026-2122.md) | Aug 31, 2026 |
| Linux | python3.14-devel amzn 2023 | 3.14.7-1.amzn2023.0.1 | [ALAS2023-2026-2122](https://patchblox.com/security/data/fix/linux/alas2023-2026-2122.md) | Aug 31, 2026 |
| Linux | python3.14-freethreading amzn 2023 | 3.14.7-1.amzn2023.0.1 | [ALAS2023-2026-2122](https://patchblox.com/security/data/fix/linux/alas2023-2026-2122.md) | Aug 31, 2026 |
| Linux | python3.14-freethreading-debug amzn 2023 | 3.14.7-1.amzn2023.0.1 | [ALAS2023-2026-2122](https://patchblox.com/security/data/fix/linux/alas2023-2026-2122.md) | Aug 31, 2026 |
| Linux | python3.14-freethreading-devel amzn 2023 | 3.14.7-1.amzn2023.0.1 | [ALAS2023-2026-2122](https://patchblox.com/security/data/fix/linux/alas2023-2026-2122.md) | Aug 31, 2026 |
| Linux | python3.14-freethreading-idle amzn 2023 | 3.14.7-1.amzn2023.0.1 | [ALAS2023-2026-2122](https://patchblox.com/security/data/fix/linux/alas2023-2026-2122.md) | Aug 31, 2026 |
| Linux | python3.14-freethreading-libs amzn 2023 | 3.14.7-1.amzn2023.0.1 | [ALAS2023-2026-2122](https://patchblox.com/security/data/fix/linux/alas2023-2026-2122.md) | Aug 31, 2026 |
| Linux | python3.14-freethreading-test amzn 2023 | 3.14.7-1.amzn2023.0.1 | [ALAS2023-2026-2122](https://patchblox.com/security/data/fix/linux/alas2023-2026-2122.md) | Aug 31, 2026 |
| Linux | python3.14-freethreading-tkinter amzn 2023 | 3.14.7-1.amzn2023.0.1 | [ALAS2023-2026-2122](https://patchblox.com/security/data/fix/linux/alas2023-2026-2122.md) | Aug 31, 2026 |
| Linux | python3.14-idle amzn 2023 | 3.14.7-1.amzn2023.0.1 | [ALAS2023-2026-2122](https://patchblox.com/security/data/fix/linux/alas2023-2026-2122.md) | Aug 31, 2026 |
| Linux | python3.14-libs amzn 2023 | 3.14.7-1.amzn2023.0.1 | [ALAS2023-2026-2122](https://patchblox.com/security/data/fix/linux/alas2023-2026-2122.md) | Aug 31, 2026 |
| Linux | python3.14-test amzn 2023 | 3.14.7-1.amzn2023.0.1 | [ALAS2023-2026-2122](https://patchblox.com/security/data/fix/linux/alas2023-2026-2122.md) | Aug 31, 2026 |
| Linux | python3.14-tkinter amzn 2023 | 3.14.7-1.amzn2023.0.1 | [ALAS2023-2026-2122](https://patchblox.com/security/data/fix/linux/alas2023-2026-2122.md) | Aug 31, 2026 |
| Linux | python313 sles 15.7 | 3.13.15-150700.4.56.1 | [SUSE-SU-2026:4401-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4401-1.md) | Sep 30, 2026 |
| Linux | python313-core sles 15.7 | 3.13.15-150700.4.56.1 | [SUSE-SU-2026:4401-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4401-1.md) | Sep 30, 2026 |

## No fix yet

| Platform | Product | Status |
|---|---|---|
| Windows apps | Python 2 | no-fix |
| Windows apps | Python 3.10 | no-fix |
| Windows apps | Python 3.11 | no-fix |
| Windows apps | Python 3.12 | no-fix |
| Windows apps | Python 3.5 | no-fix |
| Windows apps | Python 3.6 | no-fix |
| Windows apps | Python 3.7 | no-fix |
| Windows apps | Python 3.8 | no-fix |
| Windows apps | Python 3.9 | no-fix |
| macOS | Python3 | no-fix |

---

Data as of 2026-11-08T00:53:09Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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