What’s Vulnerable › Vulnerabilities

CVE-2021-26937

• Severity: critical (CVSS 9.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 9.1% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2021-02-09 · updated 2026-06-17
• Weakness: CWE-88

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.

Affected products

• Debian Linux: 9.0, 10.0
• Fedoraproject Fedora: 32, 33
• GNU Screen: through 4.8.0

References

• http://www.openwall.com/lists/oss-security/2021/02/09/8
• https://ftp.gnu.org/gnu/screen/
• https://lists.debian.org/debian-lts-announce/2021/02/msg00031.html
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/GNWBOIDEPOEQS5RMQVMFKHKXJCGNYWBL/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JJWLXP45POUUYBJRRWPVAWNZDJTLYWVM/
• https://lists.gnu.org/archive/html/screen-devel/2021-02/msg00000.html
• https://security.gentoo.org/glsa/202105-11
• https://www.debian.org/security/2021/dsa-4861
• https://www.openwall.com/lists/oss-security/2021/02/09/3
• http://www.openwall.com/lists/oss-security/2021/02/09/8
• https://ftp.gnu.org/gnu/screen/
• https://lists.debian.org/debian-lts-announce/2021/02/msg00031.html

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