urllib3: HTTPResponse.stream()/read_chunked() buffers an unbounded chunk-size line into memory
CVE-2026-97689 is fixed in 15 products on 1 platform, first by python3-urllib3 2.6.3-1ubuntu1.2, released September 29, 2026. It is not reported as exploited. Patch Radar priority: High.
urllib3 is an HTTP client library for Python. From 1.10.3 until 2.8.0, the HTTPResponse.read_chunked and HTTPResponse.stream methods can allocate unbounded memory because the streaming chunk parser buffers the chunk-size field until newline or EOF without a length bound. The trigger is that a malicious server returns Transfer-Encoding: chunked followed by a very long run of bytes without a newline. The attack mechanism is that a malicious HTTP server sends a very long unterminated chunk-size line. The impact is that unbounded memory allocation can exhaust the client process. This issue is fixed in version 2.8.0.
Where it's fixed
| Product | Fixed in | Fix | Released |
|---|---|---|---|
| Linux | |||
| python-urllib3 · Debian 14 | 2.8.0-1 | DEBIAN-CVE-2026-97689 | Sep 30, 2026 |
| python-urllib3 · RHEL 10 | 1.26.19-4.el10_2.2 | RHSA-2026:85930 | Sep 29, 2026 |
| python-urllib3 · Ubuntu 18.04.6 LTS (bionic) | 1.22-1ubuntu0.18.04.2+esm5 | python-urllib3 1.22-1ubuntu0.18.04.2+esm5 | Oct 19, 2026 |
| python-urllib3 · opensuse-leap 16.0 | 2.5.0-160000.8.1 | OPENSUSE-SU-2026:22071-1 | Nov 7, 2026 |
| python-urllib3 · rocky 10 | 0:1.26.19-4.el10_2.2 | RLSA-2026:85930 | Nov 7, 2026 |
| python-urllib3 · rocky 8 | 0:1.24.2-11.el8_10 | RLSA-2026:90759 | Nov 7, 2026 |
| python-urllib3 · rocky 9 | 0:1.26.5-8.el9_8.2 | RLSA-2026:90494 | Nov 7, 2026 |
| python-urllib3 · sles 15.6 | 2.0.7-150400.7.36.1 | SUSE-SU-2026:4704-1 | Nov 7, 2026 |
| python-urllib3 · sles 15.7 | 2.0.7-150400.7.36.1 | SUSE-SU-2026:4704-1 | Nov 7, 2026 |
| python-urllib3 · sles 16.0 | 2.5.0-160000.8.1 | SUSE-SU-2026:24217-1 | Nov 7, 2026 |
| python-urllib3_1 · sles 15.6 | 1.26.18-150600.3.14.1 | SUSE-SU-2026:4948-1 | Nov 7, 2026 |
| python-urllib3_1 · sles 15.7 | 1.26.18-150600.3.14.1 | SUSE-SU-2026:4948-1 | Nov 7, 2026 |
| python3-pip · amzn 2023 | 21.3.1-2.amzn2023.0.22 | ALAS2023-2026-3175 | Nov 7, 2026 |
| python3-pip-wheel · amzn 2023 | 21.3.1-2.amzn2023.0.22 | ALAS2023-2026-3175 | Nov 7, 2026 |
| python3-urllib3 · RHEL 8 | 0:1.24.2-11.el8_10 | RHSA-2026:90759 | Oct 29, 2026 |
| python3-urllib3 · RHEL 9 | 0:1.26.5-8.el9_8.2 | RHSA-2026:90494 | Oct 29, 2026 |
| python3-urllib3 · Ubuntu 18.04.6 LTS (bionic) | 1.22-1ubuntu0.18.04.2+esm5 | python3-urllib3 1.22-1ubuntu0.18.04.2+esm5 | Oct 19, 2026 |
| python3-urllib3 · Ubuntu 20.04 LTS (focal) | 1.25.8-2ubuntu0.4+esm6 | python3-urllib3 1.25.8-2ubuntu0.4+esm6 | Oct 19, 2026 |
| python3-urllib3 · Ubuntu 22.04.1 LTS (jammy) | 1.26.5-1~exp1ubuntu0.8 | python3-urllib3 1.26.5-1~exp1ubuntu0.8 | Oct 19, 2026 |
| python3-urllib3 · Ubuntu 24.04.5 LTS (noble) | 2.0.7-1ubuntu0.8 | python3-urllib3 2.0.7-1ubuntu0.8 | Oct 19, 2026 |
| python3-urllib3 · Ubuntu 26.04.1 LTS (resolute) | 2.6.3-1ubuntu1.2 | python3-urllib3 2.6.3-1ubuntu1.2 | Sep 29, 2026 |
| python3-urllib3 · almalinux 10 | 1.26.19-4.el10_2.2 | ALSA-2026:85930 | Nov 7, 2026 |
| python3-urllib3 · almalinux 8 | 1.24.2-11.el8_10 | ALSA-2026:90759 | Nov 7, 2026 |
| python3-urllib3 · almalinux 9 | 1.26.5-8.el9_8.2 | ALSA-2026:90494 | Nov 7, 2026 |
| python3-urllib3 · amzn 2023 | 1.25.10-5.amzn2023.0.9 | ALAS2023-2026-3184 | Nov 7, 2026 |
| python3-urllib3 · ol 10 | 0:1.26.19-4.el10_2.2 | ELSA-2026-85930 | Nov 7, 2026 |
| python3-urllib3 · ol 8 | 0:1.24.2-11.el8_10 | ELSA-2026-90759 | Nov 7, 2026 |
| python3-urllib3 · ol 9 | 0:1.26.5-8.el9_8.2 | ELSA-2026-90494 | Nov 7, 2026 |
| python3.11-pip · amzn 2023 | 22.3.1-2.amzn2023.0.15 | ALAS2023-2026-3174 | Nov 7, 2026 |
| python3.11-pip-wheel · amzn 2023 | 22.3.1-2.amzn2023.0.15 | ALAS2023-2026-3174 | Nov 7, 2026 |
| python3.12-pip · amzn 2023 | 23.2.1-4.amzn2023.0.12 | ALAS2023-2026-3173 | Nov 7, 2026 |
| python3.12-pip-wheel · amzn 2023 | 23.2.1-4.amzn2023.0.12 | ALAS2023-2026-3173 | Nov 7, 2026 |
| python3.12-urllib3 · RHEL 8 | 0:1.26.19-5.el8_10 | RHSA-2026:92474 | Oct 30, 2026 |
| python3.12-urllib3 · RHEL 9 | 0:1.26.19-3.el9_8.2 | RHSA-2026:85929 | Oct 21, 2026 |
| python3.12-urllib3 · almalinux 8 | 1.26.19-5.el8_10 | ALSA-2026:92474 | Nov 7, 2026 |
| python3.12-urllib3 · almalinux 9 | 1.26.19-3.el9_8.2 | ALSA-2026:85929 | Nov 7, 2026 |
| python3.12-urllib3 · ol 8 | 0:1.26.19-5.el8_10 | ELSA-2026-92474 | Nov 7, 2026 |
| python3.12-urllib3 · ol 9 | 0:1.26.19-3.el9_8.2 | ELSA-2026-85929 | Nov 7, 2026 |
| python3.12-urllib3 · rocky 8 | 0:1.26.19-5.el8_10 | RLSA-2026:92474 | Nov 7, 2026 |
| python3.12-urllib3 · rocky 9 | 0:1.26.19-3.el9_8.2 | RLSA-2026:85929 | Nov 7, 2026 |
| python3.13-pip · amzn 2023 | 24.2-259.amzn2023.0.9 | ALAS2023-2026-3172 | Nov 7, 2026 |
| python3.13-pip-wheel · amzn 2023 | 24.2-259.amzn2023.0.9 | ALAS2023-2026-3172 | Nov 7, 2026 |
| python3.14-pip · amzn 2023 | 26.1.1-1.amzn2023.0.4 | ALAS2023-2026-3171 | Nov 7, 2026 |
| python3.14-pip-wheel · amzn 2023 | 26.1.1-1.amzn2023.0.4 | ALAS2023-2026-3171 | Nov 7, 2026 |
| python3.14-urllib3 · RHEL 10 | 2.6.3-2.el10_2.6 | RHSA-2026:84578 | Oct 19, 2026 |
| python3.14-urllib3 · RHEL 9 | 0:2.6.3-2.el9_8.6 | RHSA-2026:84577 | Oct 19, 2026 |
| python3.14-urllib3 · almalinux 10 | 2.6.3-2.el10_2.6 | ALSA-2026:84578 | Nov 7, 2026 |
| python3.14-urllib3 · almalinux 9 | 2.6.3-2.el9_8.6 | ALSA-2026:84577 | Nov 7, 2026 |
| python3.14-urllib3 · ol 10 | 0:2.6.3-2.el10_2.6 | ELSA-2026-84578 | Nov 7, 2026 |
| python3.14-urllib3 · ol 9 | 0:2.6.3-2.el9_8.6 | ELSA-2026-84577 | Nov 7, 2026 |
| python3.14-urllib3 · rocky 10 | 0:2.6.3-2.el10_2.6 | RLSA-2026:84578 | Nov 7, 2026 |
| python3.14-urllib3 · rocky 9 | 0:2.6.3-2.el9_8.6 | RLSA-2026:84577 | Nov 7, 2026 |
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