# CVE-2018-20969: patch: The patch program applies diff files to originals

CVE-2018-20969 is fixed in patch on 1 platform, first by patch 2.7.6-2ubuntu1.1, released August 15, 2019. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2018-20969
- Priority: High
- CVSS: 7.8 (Important)
- EPSS: 0.0268
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Aug 15, 2019

## Description

The patch program applies diff files to originals. The diff command is used to compare an original to a changed file. Diff lists the changes made to the file. A person who has the original file can then use the patch command with the diff file to add the changes to their original file (patching the file).  Security Fix(es):  * patch: do_ed_script in pch.c does not block strings beginning with a ! character (CVE-2018-20969)  * patch: OS shell command injection when processing crafted patch files (CVE-2019-13638)  For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | patch RHEL 8 | 0:2.7.6-9.el8_0 | [RHSA-2019:2798](https://patchblox.com/security/data/fix/linux/rhsa-2019-2798.md) | Sep 19, 2019 |
| Linux | patch Ubuntu 18.04.6 LTS (bionic) | 2.7.6-2ubuntu1.1 | [patch 2.7.6-2ubuntu1.1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-patch-2.7.6-2ubuntu1.1.md) | Aug 15, 2019 |
| Linux | patch ol 8 | 0:2.7.6-9.el8_0 | [ELSA-2019-2798](https://patchblox.com/security/data/fix/linux/elsa-2019-2798.md) | Sep 19, 2019 |

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 Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo