CVE-2021-26937
9.8
CRITICAL · CVSS 3.1 · EPSS 9.1% (pctl 95)
In your normal cycle
Critical by CVSS (9.8), but no sign of active exploitation.
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.
Scoring
| CVSS | 9.8 (CRITICAL, v3.1) |
|---|---|
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| EPSS | 9.15% — more likely to be exploited than 95% of all CVEs |
| Weakness | CWE-88 |
| On CISA KEV | no |
| Public exploit | none known |
| Published | 2021-02-09 |
| Last modified | 2026-06-17 |
Affected (3)
| Vendor | Product |
|---|---|
| debian | debian linux |
| fedoraproject | fedora |
| gnu | screen |
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
- 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://security.netapp.com/advisory/ntap-20250509-0004/
- https://www.debian.org/security/2021/dsa-4861
- https://www.openwall.com/lists/oss-security/2021/02/09/3
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