# CVE-2021-26937: screen: encoding.c in GNU Screen through 4.8.0 allows remote attackers to cause a denial of service (invalid write access and...

CVE-2021-26937 is fixed in screen on 1 platform, first by screen 4.6.2-1ubuntu1.1, released February 9, 2021. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2021-26937
- Priority: Routine
- CVSS: n/a (Medium)
- EPSS: 0.0926
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Feb 9, 2021

## Description

encoding.c in GNU Screen through 4.8.0 allows remote attackers to cause a denial of service (invalid write access and application crash) or possibly have unspecified other impact via a crafted UTF-8 character sequence.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | screen Ubuntu 18.04.6 LTS (bionic) | 4.6.2-1ubuntu1.1 | [screen 4.6.2-1ubuntu1.1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-screen-4.6.2-1ubuntu1.1.md) | Feb 9, 2021 |
| Linux | screen Ubuntu 20.04 LTS (focal) | 4.8.0-1ubuntu0.1 | [screen 4.8.0-1ubuntu0.1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-screen-4.8.0-1ubuntu0.1.md) | Feb 9, 2021 |

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 Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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