# CVE-2021-33646: libtar0t64: The th_read() function doesn’t free a variable t->th_buf.gnu_longname afterallocating memory, which may cause a memor...

CVE-2021-33646 is fixed in 3 products on 1 platform, first by libtar0 1.2.20-7ubuntu0.1~esm1, released August 10, 2022. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2021-33646
- Priority: High
- CVSS: 7.5 (Low)
- EPSS: 0.0200
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Aug 10, 2022

## Description

The th_read() function doesn’t free a variable t->th_buf.gnu_longname afterallocating memory, which may cause a memory leak.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | libtar Debian 12.15 (bookworm) | 1.2.20-8+deb12u1 | [DEBIAN-CVE-2021-33646](https://patchblox.com/security/data/fix/linux/debian-cve-2021-33646.md) | Aug 10, 2022 |
| Linux | libtar RHEL 8 | 0:1.2.20-17.el8 | [RHSA-2023:2898](https://patchblox.com/security/data/fix/linux/rhsa-2023-2898.md) | May 16, 2023 |
| Linux | libtar almalinux 8 | 1.2.20-17.el8 | [ALSA-2023:2898](https://patchblox.com/security/data/fix/linux/alsa-2023-2898.md) | May 16, 2023 |
| Linux | libtar ol 8 | 0:1.2.20-17.el8 | [ELSA-2023-2898](https://patchblox.com/security/data/fix/linux/elsa-2023-2898.md) | May 24, 2023 |
| Linux | libtar rocky 8 | 0:1.2.20-17.el8 | [RLSA-2023:2898](https://patchblox.com/security/data/fix/linux/rlsa-2023-2898.md) | Dec 27, 2025 |
| Linux | libtar0 Ubuntu 18.04.6 LTS (bionic) | 1.2.20-7ubuntu0.1~esm1 | [libtar0 1.2.20-7ubuntu0.1~esm1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libtar0-1.2.20-7ubuntu0.1-esm1.md) | Aug 10, 2022 |
| Linux | libtar0 Ubuntu 20.04 LTS (focal) | 1.2.20-8ubuntu0.20.04.1 | [libtar0 1.2.20-8ubuntu0.20.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-libtar0-1.2.20-8ubuntu0.20.04.1.md) | Aug 10, 2022 |
| Linux | libtar0 Ubuntu 22.04.1 LTS (jammy) | 1.2.20-8ubuntu0.22.04.1 | [libtar0 1.2.20-8ubuntu0.22.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-libtar0-1.2.20-8ubuntu0.22.04.1.md) | Aug 10, 2022 |
| Linux | libtar0t64 Ubuntu 24.04.5 LTS (noble) | 1.2.20-8.1ubuntu0.24.04.1 | [libtar0t64 1.2.20-8.1ubuntu0.24.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-noble-libtar0t64-1.2.20-8.1ubuntu0.24.04.1.md) | Aug 10, 2022 |
| Linux | libtar0t64 Ubuntu 24.10 (oracular) | 1.2.20-8.1ubuntu0.24.10.1 | [libtar0t64 1.2.20-8.1ubuntu0.24.10.1](https://patchblox.com/security/data/fix/linux/ubuntu-oracular-libtar0t64-1.2.20-8.1ubuntu0.24.10.1.md) | Jan 16, 2026 |

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Data as of 2026-11-08T13:06:02Z 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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