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Vulnerability details: VCID-ezsn-vvex-gkah
Vulnerability ID VCID-ezsn-vvex-gkah
Aliases CVE-2021-26720
Summary avahi-daemon-check-dns.sh in the Debian avahi package through 0.8-4 is executed as root via /etc/network/if-up.d/avahi-daemon, and allows a local attacker to cause a denial of service or create arbitrary empty files via a symlink attack on files under /run/avahi-daemon. NOTE: this only affects the packaging for Debian GNU/Linux (used indirectly by SUSE), not the upstream Avahi product.
Status Published
Exploitability 0.5
Weighted Severity 3.9
Risk 1.9
Affected and Fixed Packages Package Details
Weaknesses (0)
There are no known CWE.
System Score Found at
epss 0.00069 https://api.first.org/data/v1/epss?cve=CVE-2021-26720
epss 0.00069 https://api.first.org/data/v1/epss?cve=CVE-2021-26720
epss 0.00069 https://api.first.org/data/v1/epss?cve=CVE-2021-26720
epss 0.00069 https://api.first.org/data/v1/epss?cve=CVE-2021-26720
epss 0.00069 https://api.first.org/data/v1/epss?cve=CVE-2021-26720
epss 0.00069 https://api.first.org/data/v1/epss?cve=CVE-2021-26720
epss 0.00069 https://api.first.org/data/v1/epss?cve=CVE-2021-26720
epss 0.00069 https://api.first.org/data/v1/epss?cve=CVE-2021-26720
epss 0.00069 https://api.first.org/data/v1/epss?cve=CVE-2021-26720
cvssv3.1 7.8 https://ftp.suse.com/pub/projects/security/yaml/suse-cvss-scores.yaml
Reference id Reference type URL
https://api.first.org/data/v1/epss?cve=CVE-2021-26720
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-26720
https://ftp.suse.com/pub/projects/security/yaml/suse-cvss-scores.yaml
No exploits are available.
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Found at https://ftp.suse.com/pub/projects/security/yaml/suse-cvss-scores.yaml
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Exploit Prediction Scoring System (EPSS)
Percentile 0.21148
EPSS Score 0.00069
Published At April 1, 2026, 12:55 p.m.
Date Actor Action Source VulnerableCode Version
2026-04-01T16:34:43.032605+00:00 Debian Oval Importer Import https://www.debian.org/security/oval/oval-definitions-bullseye.xml.bz2 38.0.0