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Vulnerability record · CVE-2021-26937 · published 9 February 2021

CVE-2021-26937: Gnu screen argument injection vulnerability

Gnu · Screen

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.

9.8 CVSS 3.1 Critical EPSS 9.1% · top 4.8% CWE-88 · Argument injection
9.8CVSS 3.1 base score, v2 7.5
9.1%EPSS exploitation probability, 30 days
NoNot in CISA KEV
3Affected product versions listed by NVD
19References, 6 tagged exploit
17 Jun 2026Last modified by NVD

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.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

3 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
http://www.openwall.com/lists/oss-security/2021/02/09/8 ExploitMailing ListThird Party Advisory
https://ftp.gnu.org/gnu/screen/ Product
https://lists.debian.org/debian-lts-announce/2021/02/msg00031.html Mailing ListThird Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/GNWBOIDEPOEQS5RMQVMFKHK
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JJWLXP45POUUYBJRRWPVAWN
https://lists.gnu.org/archive/html/screen-devel/2021-02/msg00000.html ExploitMailing ListVendor Advisory
https://security.gentoo.org/glsa/202105-11 Third Party Advisory
https://www.debian.org/security/2021/dsa-4861 Third Party Advisory
https://www.openwall.com/lists/oss-security/2021/02/09/3 ExploitMailing ListThird Party Advisory
http://www.openwall.com/lists/oss-security/2021/02/09/8 ExploitMailing ListThird Party Advisory
https://ftp.gnu.org/gnu/screen/ Product
https://lists.debian.org/debian-lts-announce/2021/02/msg00031.html Mailing ListThird Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/GNWBOIDEPOEQS5RMQVMFKHK
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JJWLXP45POUUYBJRRWPVAWN
https://lists.gnu.org/archive/html/screen-devel/2021-02/msg00000.html ExploitMailing ListVendor Advisory
https://security.gentoo.org/glsa/202105-11 Third Party Advisory
https://security.netapp.com/advisory/ntap-20250509-0004/
https://www.debian.org/security/2021/dsa-4861 Third Party Advisory
https://www.openwall.com/lists/oss-security/2021/02/09/3 ExploitMailing ListThird Party Advisory

Track CVE-2021-26937 inside VULONE

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Source: NIST National Vulnerability Database (record CVE-2021-26937), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.