# squid3 security updates

Patch Radar has 21 security fixes for squid3, closing 51 CVEs. The newest security fix is squid3 3.5.27-1ubuntu1.14+esm6, released October 24, 2026.

- Web page: https://patchblox.com/security/product/linux/squid3
- Platform: Linux
- Supported: yes

## Security fixes, newest first

| Fix | Released | Fixed in | Priority | CVEs | Exploited |
|---|---|---|---|---:|---:|
| [squid3 3.5.27-1ubuntu1.14+esm6](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-squid3-3.5.27-1ubuntu1.14-esm6.md) | Oct 24, 2026 | Ubuntu 18.04.6 LTS (bionic) 3.5.27-1ubuntu1.14+esm6 | High | 6 | 0 |
| [squid3 3.5.27-1ubuntu1.14+esm4](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-squid3-3.5.27-1ubuntu1.14-esm4.md) | Oct 20, 2025 | Ubuntu 18.04.6 LTS (bionic) 3.5.27-1ubuntu1.14+esm4 | Urgent | 1 | 0 |
| [squid3 3.5.27-1ubuntu1.14+esm5](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-squid3-3.5.27-1ubuntu1.14-esm5.md) | Sep 26, 2025 | Ubuntu 18.04.6 LTS (bionic) 3.5.27-1ubuntu1.14+esm5 | High | 1 | 0 |
| [squid3 3.5.27-1ubuntu1.14+esm3](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-squid3-3.5.27-1ubuntu1.14-esm3.md) | Jun 25, 2024 | Ubuntu 18.04.6 LTS (bionic) 3.5.27-1ubuntu1.14+esm3 | Routine | 1 | 0 |
| [squid3 3.5.27-1ubuntu1.14+esm2](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-squid3-3.5.27-1ubuntu1.14-esm2.md) | Feb 14, 2024 | Ubuntu 18.04.6 LTS (bionic) 3.5.27-1ubuntu1.14+esm2 | High | 4 | 0 |
| [squid3 3.5.27-1ubuntu1.14+esm1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-squid3-3.5.27-1ubuntu1.14-esm1.md) | Nov 6, 2023 | Ubuntu 18.04.6 LTS (bionic) 3.5.27-1ubuntu1.14+esm1 | Urgent | 2 | 0 |
| [squid3 3.5.27-1ubuntu1.14](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-squid3-3.5.27-1ubuntu1.14.md) | Sep 22, 2022 | Ubuntu 18.04.6 LTS (bionic) 3.5.27-1ubuntu1.14 | High | 1 | 0 |
| [squid3 3.5.27-1ubuntu1.13](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-squid3-3.5.27-1ubuntu1.13.md) | Dec 30, 2021 | Ubuntu 18.04.6 LTS (bionic) 3.5.27-1ubuntu1.13 | High | 1 | 0 |
| [squid3 3.5.27-1ubuntu1.11](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-squid3-3.5.27-1ubuntu1.11.md) | May 28, 2021 | Ubuntu 18.04.6 LTS (bionic) 3.5.27-1ubuntu1.11 | High | 6 | 0 |
| [squid3 3.5.27-1ubuntu1.10](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-squid3-3.5.27-1ubuntu1.10.md) | Mar 18, 2021 | Ubuntu 18.04.6 LTS (bionic) 3.5.27-1ubuntu1.10 | High | 1 | 0 |
| [squid3 3.5.27-1ubuntu1.12](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-squid3-3.5.27-1ubuntu1.12.md) | Mar 9, 2021 | Ubuntu 18.04.6 LTS (bionic) 3.5.27-1ubuntu1.12 | Routine | 1 | 0 |
| [squid3 3.5.27-1ubuntu1.9](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-squid3-3.5.27-1ubuntu1.9.md) | Aug 24, 2020 | Ubuntu 18.04.6 LTS (bionic) 3.5.27-1ubuntu1.9 | High | 4 | 0 |
| [squid3 3.5.27-1ubuntu1.6](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-squid3-3.5.27-1ubuntu1.6.md) | Apr 23, 2020 | Ubuntu 18.04.6 LTS (bionic) 3.5.27-1ubuntu1.6 | High | 4 | 0 |
| [squid3 3.5.27-1ubuntu1.7](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-squid3-3.5.27-1ubuntu1.7.md) | Apr 15, 2020 | Ubuntu 18.04.6 LTS (bionic) 3.5.27-1ubuntu1.7 | High | 4 | 0 |
| [squid3 3.5.27-1ubuntu1.5](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-squid3-3.5.27-1ubuntu1.5.md) | Feb 4, 2020 | Ubuntu 18.04.6 LTS (bionic) 3.5.27-1ubuntu1.5 | High | 4 | 0 |
| [squid3 4.9-2ubuntu4](https://patchblox.com/security/data/fix/linux/ubuntu-focal-squid3-4.9-2ubuntu4.md) | Feb 4, 2020 | Ubuntu 20.04 LTS (focal) 4.9-2ubuntu4 | High | 4 | 0 |
| [squid3 4.9-2ubuntu1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-squid3-4.9-2ubuntu1.md) | Nov 26, 2019 | Ubuntu 20.04 LTS (focal) 4.9-2ubuntu1 | High | 6 | 0 |
| [squid3 3.5.27-1ubuntu1.4](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-squid3-3.5.27-1ubuntu1.4.md) | Nov 26, 2019 | Ubuntu 18.04.6 LTS (bionic) 3.5.27-1ubuntu1.4 | High | 4 | 0 |
| [squid3 3.5.27-1ubuntu1.3](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-squid3-3.5.27-1ubuntu1.3.md) | Jul 10, 2019 | Ubuntu 18.04.6 LTS (bionic) 3.5.27-1ubuntu1.3 | High | 2 | 0 |
| [squid3 3.5.27-1ubuntu1.2](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-squid3-3.5.27-1ubuntu1.2.md) | Jul 4, 2019 | Ubuntu 18.04.6 LTS (bionic) 3.5.27-1ubuntu1.2 | Routine | 2 | 0 |
| [squid3 3.5.23-5ubuntu2](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-squid3-3.5.23-5ubuntu2.md) | Jan 28, 2018 | Ubuntu 18.04.6 LTS (bionic) 3.5.23-5ubuntu2 | Routine | 2 | 0 |

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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

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