# CVE-2023-43804: `Cookie` HTTP header isn't stripped on cross-origin redirects > Attackers can steal cookies via cross-origin redirects if users manually set Cookie headers without disabling redirects in urllib3. - **Severity:** Medium 5.9 (`CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:N`) - **Exploited in the wild:** Not known - **Login needed:** An administrator - **Attackable:** Over the internet - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 4 Oct 2023 - **Updated:** 3 Nov 2025 - **Also known as:** ALPINE-CVE-2023-43804, ALSA-2024:2159, ALSA-2024:2986, AZL-31108, AZL-35444, AZL-59696, BELL-CVE-2023-43804, CLEANSTART-2026-FO12230, CLEANSTART-2026-II63303, CLSA-2025-1763032859, CLSA-2026-1769645563, DEBIAN-CVE-2023-43804, GHSA-v845-jxx5-vc9f, MINI-mfmc-w52h-cqm6, OESA-2023-1707, PYSEC-2023-192, RHSA-2024:0187, RHSA-2024:2159, RHSA-2024:2986, RLSA-2024:2986, ROOT-APP-PYPI-CVE-2023-43804, SUSE-SU-2023:4064-1, SUSE-SU-2023:4108-1, SUSE-SU-2023:4157-1, UBUNTU-CVE-2023-43804, openSUSE-SU-2024:13301-1, openSUSE-SU-2024:13302-1 ## What is CVE-2023-43804? CVE-2023-43804 is a medium-severity vulnerability in Debian Debian Linux, published on 4 Oct 2023. An attacker needs administrator access to exploit it, with no action from the victim. ### Official description urllib3 is a user-friendly HTTP client library for Python. urllib3 doesn't treat the `Cookie` HTTP header special or provide any helpers for managing cookies over HTTP, that is the responsibility of the user. However, it is possible for a user to specify a `Cookie` header and unknowingly leak information via HTTP redirects to a different origin if that user doesn't disable redirects explicitly. This issue has been patched in urllib3 version 1.26.17 or 2.0.5. Weakness: CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor) ## Which versions are affected by CVE-2023-43804? 5 open source packages ship an affected version, including urllib3. It affects 3 products. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `urllib3` | PyPI | All versions | 1.26.17 | | `urllib3` | PyPI | All versions | 1.26.17 | | `urllib3` | PyPI | From 2.0.0 | 2.0.6, 1.26.17 | | `urllib3` | PyPI | From 2.0.0 | 2.0.6 | | `urllib3` | PyPI | From 2.0.0 | 2.0.6 | | `python3.11-urllib3` | AlmaLinux:8 | All versions | 1.26.12-2.el8 | | `python3.11-urllib3` | AlmaLinux:9 | All versions | 1.26.12-2.el9 | | `python3.11-urllib3` | Red Hat:enterprise_linux:8::appstream | All versions | 0:1.26.12-2.el8 | | `python3.11-urllib3` | Red Hat:enterprise_linux:9::appstream | All versions | 0:1.26.12-2.el9 | | `python-urllib3` | Red Hat:openstack:17.1::el8 | All versions | 0:1.25.10-5.el8ost | | `python3-urllib3` | Red Hat:openstack:17.1::el8 | All versions | 0:1.25.10-5.el8ost | | `python3.11-urllib3` | Rocky Linux:8 | All versions | 0:1.26.12-2.el8 | | `python-urllib3` | SUSE:HPE Helion OpenStack 8 | All versions | 1.25.10-5.22.1 | | `python-urllib3` | SUSE:Linux Enterprise Micro 5.1 | All versions | 1.25.10-150300.4.6.1 | | `python-urllib3` | SUSE:Linux Enterprise Micro 5.2 | All versions | 1.25.10-150300.4.6.1 | | `python-urllib3` | SUSE:Linux Enterprise Micro 5.3 | All versions | 1.25.10-150300.4.6.1 | | `python-urllib3` | SUSE:Linux Enterprise Micro 5.4 | All versions | 1.25.10-150300.4.6.1 | | `python-urllib3` | SUSE:Linux Enterprise Micro 5.5 | All versions | 1.25.10-150300.4.6.1 | | `python-urllib3` | SUSE:Linux Enterprise Module for Basesystem 15 SP4 | All versions | 1.25.10-150300.4.6.1 | | `python-urllib3` | SUSE:Linux Enterprise Module for Basesystem 15 SP5 | All versions | 1.25.10-150300.4.6.1 | | `python-urllib3` | SUSE:Linux Enterprise Module for Public Cloud 12 | All versions | 1.25.10-3.34.1 | | `python-urllib3` | SUSE:Linux Enterprise Server 12 SP5 | All versions | 1.25.10-3.34.1 | | `python-urllib3` | SUSE:Linux Enterprise Server for SAP Applications 12 SP5 | All versions | 1.25.10-3.34.1 | | `python-urllib3` | SUSE:Linux Enterprise Software Development Kit 12 SP5 | All versions | 1.25.10-3.34.1 | | `python-urllib3` | SUSE:Linux Enterprise Workstation Extension 12 SP5 | All versions | 1.25.10-3.34.1 | | `python-urllib3` | SUSE:Manager Proxy 4.2 | All versions | 1.25.10-150300.4.6.1 | | `python-urllib3` | SUSE:Manager Server 4.2 | All versions | 1.25.10-150300.4.6.1 | | `python-urllib3` | SUSE:OpenStack Cloud 8 | All versions | 1.25.10-5.22.1 | | `python-urllib3` | SUSE:OpenStack Cloud Crowbar 8 | All versions | 1.25.10-5.22.1 | | `python-urllib3` | openSUSE:Tumbleweed | All versions | 2.0.6-1.1 | Products: Debian Debian Linux, Fedoraproject Fedora, Python Urllib3. ## How do I fix CVE-2023-43804? Upgrade urllib3 to a fixed version for your release line: 1.26.17 or 2.0.6. ## Is CVE-2023-43804 being exploited? There is no known exploitation of CVE-2023-43804 in the wild and no public exploit code. Public exploit code: - https://github.com/deepanshu-khurana/CVE-2023-43804 (github_poc): https://github.com/deepanshu-khurana/CVE-2023-43804 ## Other vulnerabilities in Debian Debian Linux - [CVE-2015-3306](https://insights.sbomify.com/CVE-2015-3306/): ProFTPD Improper Access Control (critical 10.0, exploited in the wild) - [CVE-2025-49113](https://insights.sbomify.com/CVE-2025-49113/): RoundCube Webmail Deserialization of Untrusted Data (critical 9.9, exploited in the wild) - [CVE-2026-24061](https://insights.sbomify.com/CVE-2026-24061/): GNU InetUtils Argument Injection (critical 9.8, exploited in the wild) - [CVE-2025-39682](https://insights.sbomify.com/CVE-2025-39682/): Linux Kernel Improper Check for Unusual or Exceptional Conditions (critical 9.8, exploited in the wild) - [CVE-2024-9680](https://insights.sbomify.com/CVE-2024-9680/): Mozilla Firefox Use-After-Free (critical 9.8, exploited in the wild) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2023-43804 and fix it if it is affected. What it is: CVE-2023-43804 is a medium-severity vulnerability in Debian Debian Linux, published on 4 Oct 2023. An attacker needs administrator access to exploit it, with no action from the victim. Exploitation: There is no known exploitation of CVE-2023-43804 in the wild and no public exploit code. Affected packages and fixed versions: - urllib3 (PyPI): affected all versions; fixed in 1.26.17 - urllib3 (PyPI): affected all versions; fixed in 1.26.17 - urllib3 (PyPI): affected from 2.0.0; fixed in 2.0.6, 1.26.17 - urllib3 (PyPI): affected from 2.0.0; fixed in 2.0.6 - urllib3 (PyPI): affected from 2.0.0; fixed in 2.0.6 Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2023-43804/ (Markdown: https://insights.sbomify.com/CVE-2023-43804/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2023-43804 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-43804 - OSV: https://osv.dev/vulnerability/CVE-2023-43804 --- From sbomify Insights: https://insights.sbomify.com/CVE-2023-43804/ Summaries are generated and may contain mistakes; the official description above is the record.