# RHSA-2021:1633: Security update for 7 packages

RHSA-2021:1633, released May 18, 2021, fixes 4 CVEs across 7 products. None of them is reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/fix/linux/rhsa-2021-1633
- Platform: Linux
- Released: May 18, 2021
- Priority: High (Closes CVE-2021-23336, high severity)
- CVEs: 4, exploited: 0, on CISA KEV: 0
- Vendor advisory: https://access.redhat.com/errata/RHSA-2021:1633

## Applies to

| Product | Release | Fixed in |
|---|---|---|
| [platform-python](https://patchblox.com/security/data/product/linux/platform-python.md) | RHEL 8 | 0:3.6.8-37.el8 |
| [platform-python-debug](https://patchblox.com/security/data/product/linux/platform-python-debug.md) | RHEL 8 | 0:3.6.8-37.el8 |
| [platform-python-devel](https://patchblox.com/security/data/product/linux/platform-python-devel.md) | RHEL 8 | 0:3.6.8-37.el8 |
| [python3-idle](https://patchblox.com/security/data/product/linux/python3-idle.md) | RHEL 8 | 0:3.6.8-37.el8 |
| [python3-libs](https://patchblox.com/security/data/product/linux/python3-libs.md) | RHEL 8 | 0:3.6.8-37.el8 |
| [python3-test](https://patchblox.com/security/data/product/linux/python3-test.md) | RHEL 8 | 0:3.6.8-37.el8 |
| [python3-tkinter](https://patchblox.com/security/data/product/linux/python3-tkinter.md) | RHEL 8 | 0:3.6.8-37.el8 |

## CVEs this fix closes

| CVE | Priority | Title | CVSS | EPSS | Exploitation |
|---|---|---|---:|---:|---|
| [CVE-2021-23336](https://patchblox.com/security/data/cve/CVE-2021-23336.md) | High | Web Cache Poisoning | 9.1 | 0.4074 |  |
| [CVE-2021-3177](https://patchblox.com/security/data/cve/CVE-2021-3177.md) | High | Python 3.7 and 2 others: Buffer Copy without Checking Size of Input ('Classic Buffer Overflow') | 9.8 | 0.2400 |  |
| [CVE-2020-27619](https://patchblox.com/security/data/cve/CVE-2020-27619.md) | High | Python 3.7 and 3 others: In Python 3 through 3.9.0, the Lib/test/multibytecodec_support.py CJK codec tests call eval() on content… | 9.8 | 0.0833 |  |
| [CVE-2020-26116](https://patchblox.com/security/data/cve/CVE-2020-26116.md) | High | Python 3.6 and 3 others: http.client in Python 3.x before 3.5.10, 3.6.x before 3.6.12, 3.7.x before 3.7.9, and 3.8.x before 3.8.5… | 7.2 | 0.0636 |  |

---

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 Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo