Avahi
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By the Year
In 2026 there have been 5 vulnerabilities in Avahi with an average score of 6.1 out of ten. Last year, in 2025 Avahi had 1 security vulnerability published. That is, 4 more vulnerabilities have already been reported in 2026 as compared to last year. However, the average CVE base score of the vulnerabilities in 2026 is greater by 0.60.
| Year | Vulnerabilities | Average Score |
|---|---|---|
| 2026 | 5 | 6.10 |
| 2025 | 1 | 5.50 |
| 2024 | 2 | 5.30 |
| 2023 | 6 | 6.08 |
| 2022 | 0 | 0.00 |
| 2021 | 3 | 6.27 |
It may take a day or so for new Avahi vulnerabilities to show up in the stats or in the list of recent security vulnerabilities. Additionally vulnerabilities may be tagged under a different product or component name.
Recent Avahi Security Vulnerabilities
Avahi <0.9-rc4 D-Bus Publish Flags Trigger Unprivileged Crash
CVE-2026-34933
5.5 - Medium
- April 03, 2026
Avahi is a system which facilitates service discovery on a local network via the mDNS/DNS-SD protocol suite. Prior to version 0.9-rc4, any unprivileged local user can crash avahi-daemon by sending a single D-Bus method call with conflicting publish flags. This issue has been patched in version 0.9-rc4.
assertion failure
Avahi <=0.9rc2: Segfault via Recursive CNAME in mDNS
CVE-2026-24401
6.5 - Medium
- January 24, 2026
Avahi is a system which facilitates service discovery on a local network via the mDNS/DNS-SD protocol suite. In versions 0.9rc2 and below, avahi-daemon can be crashed via a segmentation fault by sending an unsolicited mDNS response containing a recursive CNAME record, where the alias and canonical name point to the same domain (e.g., "h.local" as a CNAME for "h.local"). This causes unbounded recursion in the lookup_handle_cname function, leading to stack exhaustion. The vulnerability affects record browsers where AVAHI_LOOKUP_USE_MULTICAST is set explicitly, which includes record browsers created by resolvers used by nss-mdns. This issue is patched in commit 78eab31128479f06e30beb8c1cbf99dd921e2524.
Stack Exhaustion
Avahi 0.9-rc2 Daemon Crash via 2 CNAME RRs
CVE-2025-68471
6.5 - Medium
- January 12, 2026
Avahi is a system which facilitates service discovery on a local network via the mDNS/DNS-SD protocol suite. In 0.9-rc2 and earlier, avahi-daemon can be crashed by sending 2 unsolicited announcements with CNAME resource records 2 seconds apart.
assertion failure
Avahi 0.9-rc2: avahi-daemon crash via short TTL CNAME (CVE-2025-68468)
CVE-2025-68468
6.5 - Medium
- January 12, 2026
Avahi is a system which facilitates service discovery on a local network via the mDNS/DNS-SD protocol suite. In 0.9-rc2 and earlier, avahi-daemon can be crashed by sending unsolicited announcements containing CNAME resource records pointing it to resource records with short TTLs. As soon as they expire avahi-daemon crashes.
assertion failure
Avahi <0.9-rc2 Crash via D-Bus RecordBrowser misuse
CVE-2025-68276
5.5 - Medium
- January 12, 2026
Avahi is a system which facilitates service discovery on a local network via the mDNS/DNS-SD protocol suite. In 0.9-rc2 and earlier, an unprivileged local users can crash avahi-daemon (with wide-area disabled) by creating record browsers with the AVAHI_LOOKUP_USE_WIDE_AREA flag set via D-Bus. This can be done by either calling the RecordBrowserNew method directly or creating hostname/address/service resolvers/browsers that create those browsers internally themselves.
assertion failure
Avahi v0.9-rc2 Simple Server DoS via Unlimited Connections
CVE-2025-59529
5.5 - Medium
- December 18, 2025
Avahi is a system which facilitates service discovery on a local network via the mDNS/DNS-SD protocol suite. In versions up to and including 0.9-rc2, the simple protocol server ignores the documented client limit and accepts unlimited connections, allowing for easy local DoS. Although `CLIENTS_MAX` is defined, `server_work()` unconditionally `accept()`s and `client_new()` always appends the new client and increments `n_clients`. There is no check against the limit. When client cannot be accepted as a result of maximal socket number of avahi-daemon, it logs unconditionally error per each connection. Unprivileged local users can exhaust daemon memory and file descriptors, causing a denial of service system-wide for mDNS/DNS-SD. Exhausting local file descriptors causes increased system load caused by logging errors of each of request. Overloading prevents glibc calls using nss-mdns plugins to resolve `*.local.` names and link-local addresses. As of time of publication, no known patched versions are available, but a candidate fix is available in pull request 808, and some workarounds are available. Simple clients are offered for nss-mdns package functionality. It is not possible to disable the unix socket `/run/avahi-daemon/socket`, but resolution requests received via DBus are not affected directly. Tools avahi-resolve, avahi-resolve-address and avahi-resolve-host-name are not affected, they use DBus interface. It is possible to change permissions of unix socket after avahi-daemon is started. But avahi-daemon does not provide any configuration for it. Additional access restrictions like SELinux can also prevent unwanted tools to access the socket and keep resolution working for trusted users.
Resource Exhaustion
Avahi-daemon: Fixed Source Port Vulnerability in Wide-Area DNS Queries
CVE-2024-52615
5.3 - Medium
- November 21, 2024
A flaw was found in Avahi-daemon, which relies on fixed source ports for wide-area DNS queries. This issue simplifies attacks where malicious DNS responses are injected.
Use of Insufficiently Random Values
Avahi-daemon DNS Transaction ID Predictability Vulnerability
CVE-2024-52616
5.3 - Medium
- November 21, 2024
A flaw was found in the Avahi-daemon, where it initializes DNS transaction IDs randomly only once at startup, incrementing them sequentially after that. This predictable behavior facilitates DNS spoofing attacks, allowing attackers to guess transaction IDs.
Small Space of Random Values
Avahi reachable assertion flaw in avahi_alternative_host_name()
CVE-2023-38473
6.2 - Medium
- November 02, 2023
A vulnerability was found in Avahi. A reachable assertion exists in the avahi_alternative_host_name() function.
assertion failure
Avahi Reachable Assertion in avahi_escape_label()
CVE-2023-38470
6.2 - Medium
- November 02, 2023
A vulnerability was found in Avahi. A reachable assertion exists in the avahi_escape_label() function.
assertion failure
Avahi Assertion Failure in DNS Packet Append (CVE-2023-38469)
CVE-2023-38469
6.2 - Medium
- November 02, 2023
A vulnerability was found in Avahi, where a reachable assertion exists in avahi_dns_packet_append_record.
assertion failure
Avahi Reachable Assertion in dbus_set_host_name (CVE-2023-38471)
CVE-2023-38471
6.2 - Medium
- November 02, 2023
A vulnerability was found in Avahi. A reachable assertion exists in the dbus_set_host_name function.
assertion failure
Avahi mDNS Daemon: Assertion Failure in avahi_rdata_parse()
CVE-2023-38472
6.2 - Medium
- November 02, 2023
A vulnerability was found in Avahi. A reachable assertion exists in the avahi_rdata_parse() function.
assertion failure
Avahi Lib: Unprivileged D-Bus Crash (CVE-2023-1981)
CVE-2023-1981
5.5 - Medium
- May 26, 2023
A vulnerability was found in the avahi library. This flaw allows an unprivileged user to make a dbus call, causing the avahi daemon to crash.
Resource Exhaustion
A flaw was found in avahi in versions 0.6 up to 0.8
CVE-2021-3468
5.5 - Medium
- June 02, 2021
A flaw was found in avahi in versions 0.6 up to 0.8. The event used to signal the termination of the client connection on the avahi Unix socket is not correctly handled in the client_work function, allowing a local attacker to trigger an infinite loop. The highest threat from this vulnerability is to the availability of the avahi service, which becomes unresponsive after this flaw is triggered.
Infinite Loop
A flaw was found in avahi 0.8-5
CVE-2021-3502
5.5 - Medium
- May 07, 2021
A flaw was found in avahi 0.8-5. A reachable assertion is present in avahi_s_host_name_resolver_start function allowing a local attacker to crash the avahi service by requesting hostname resolutions through the avahi socket or dbus methods for invalid hostnames. The highest threat from this vulnerability is to the service availability.
NULL Pointer Dereference
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
CVE-2021-26720
7.8 - High
- February 17, 2021
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.
insecure temporary file
avahi-daemon in Avahi through 0.6.32 and 0.7 inadvertently responds to IPv6 unicast queries with source addresses
CVE-2017-6519
9.1 - Critical
- May 01, 2017
avahi-daemon in Avahi through 0.6.32 and 0.7 inadvertently responds to IPv6 unicast queries with source addresses that are not on-link, which allows remote attackers to cause a denial of service (traffic amplification) and may cause information leakage by obtaining potentially sensitive information from the responding device via port-5353 UDP packets. NOTE: this may overlap CVE-2015-2809.
Origin Validation Error
avahi-core/socket.c in avahi-daemon in Avahi before 0.6.29
CVE-2011-1002
- February 22, 2011
avahi-core/socket.c in avahi-daemon in Avahi before 0.6.29 allows remote attackers to cause a denial of service (infinite loop) via an empty mDNS (1) IPv4 or (2) IPv6 UDP packet to port 5353. NOTE: this vulnerability exists because of an incorrect fix for CVE-2010-2244.
Infinite Loop
