# RHSA-2026:1087: python3-urllib3 security update

RHSA-2026:1087, released January 26, 2026, fixes 3 CVEs in python3-urllib3 (version 0:1.26.5-6.el9_7.1). None of them is reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/fix/linux/rhsa-2026-1087
- Platform: Linux
- Released: Jan 26, 2026
- Priority: High (Closes CVE-2026-21441, high severity)
- CVEs: 3, exploited: 0, on CISA KEV: 0
- Vendor advisory: https://access.redhat.com/errata/RHSA-2026:1087

## Applies to

| Product | Release | Fixed in |
|---|---|---|
| [python3-urllib3](https://patchblox.com/security/data/product/linux/python3-urllib3.md) | RHEL 9 | 0:1.26.5-6.el9_7.1 |

## CVEs this fix closes

| CVE | Priority | Title | CVSS | EPSS | Exploitation |
|---|---|---|---:|---:|---|
| [CVE-2026-21441](https://patchblox.com/security/data/cve/CVE-2026-21441.md) | High | urllib3 vulnerable to decompression-bomb safeguard bypass when following HTTP redirects (streaming API) | 7.5 | 0.0292 |  |
| [CVE-2025-66418](https://patchblox.com/security/data/cve/CVE-2025-66418.md) | High | urllib3 allows an unbounded number of links in the decompression chain | 7.5 | 0.0073 |  |
| [CVE-2025-66471](https://patchblox.com/security/data/cve/CVE-2025-66471.md) | High | urllib3 Streaming API improperly handles highly compressed data | 7.5 | 0.0073 |  |

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Data as of 2026-11-07T12:40:37Z 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 Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo