Unbound
by Nlnetlabs
Source repositories
CVEs (71)
| CVE | Vendor / Product | Sev | Risk | CVSS | EPSS | KEV | Published | Description |
|---|---|---|---|---|---|---|---|---|
| CVE-2026-44690 | Hig | 0.42 | 7.5 | 0.00 | Jul 22, 2026 | In NLnet Labs Unbound 1.7.0 up to and including 1.25.1, insufficient validation of the RRSIG.Labels field combined with premature cache writes during RFC 8198 aggressive NSEC processing leads to cache poisoning that permits a malicious actor controlling a single delegated zone… | ||
| CVE-2026-40691 | Hig | 0.42 | 7.5 | 0.00 | Jul 22, 2026 | In Unbound 1.9.0 up to and including 1.25.1, when a DNSCrypt query is received over TCP, the routine that encrypts the reply in place fails to bound the reply length against the destination buffer size. The size clamp that protects the UDP path is not applied on the TCP path, so… | ||
| CVE-2026-32665 | Hig | 0.42 | 7.5 | 0.00 | Jul 22, 2026 | In NLnet Labs Unbound 1.22.0 up to and including 1.25.1, when downstream DNS-over-QUIC (DoQ) is enabled, the first two bidirectional streams on a new QUIC connection (stream_id 0 and 4) bypass the per-stream 'quic-size' gate entirely, and large input buffers are allocated later,… | ||
| CVE-2026-42959 | Hig | 0.42 | 7.5 | 0.01 | May 20, 2026 | NLnet Labs Unbound up to and including version 1.25.0 has a denial of service vulnerability in the DNSSEC validator that can lead to a crash given malicious upstream replies. When Unbound constructs chase-reply messages for validation, the code uses the wrong counter to… | ||
| CVE-2026-42944 | Hig | 0.42 | 7.5 | 0.01 | May 20, 2026 | NLnet Labs Unbound 1.14.0 up to and including version 1.25.0 has a vulnerability that results in heap overflow when encoding multiple NSID and/or DNS Cookie EDNS and/or EDNS Padding options in the reply packet. The relevant options ('nsid', 'answer-cookie', 'pad-responses'… | ||
| CVE-2026-41292 | Hig | 0.42 | 7.5 | 0.01 | May 20, 2026 | NLnet Labs Unbound up to and including version 1.25.0 is vulnerable to a degradation of service attack related to parsing long lists of incoming EDNS options. An adversary sending queries with too many EDNS options can hold Unbound threads hostage while they are parsing and… | ||
| CVE-2026-40622 | Hig | 0.42 | 7.5 | 0.00 | May 20, 2026 | NLnet Labs Unbound 1.16.2 up to and including version 1.25.0 has a vulnerability of the 'ghost domain names' family of attacks that could extend the ghost domain window by up to one cached TTL configured value. Similar to other 'ghost domain names' attacks, an adversary needs to… | ||
| CVE-2024-33655 | Hig | 0.42 | 7.5 | 0.02 | Jun 6, 2024 | The DNS protocol in RFC 1035 and updates allows remote attackers to cause a denial of service (resource consumption) by arranging for DNS queries to be accumulated for seconds, such that responses are later sent in a pulsing burst (which can be considered traffic amplification… | ||
| CVE-2022-30699 | Med | 0.42 | 6.5 | 0.01 | Aug 1, 2022 | NLnet Labs Unbound, up to and including version 1.16.1, is vulnerable to a novel type of the "ghost domain names" attack. The vulnerability works by targeting an Unbound instance. Unbound is queried for a rogue domain name when the cached delegation information is about to… | ||
| CVE-2022-30698 | Med | 0.42 | 6.5 | 0.01 | Aug 1, 2022 | NLnet Labs Unbound, up to and including version 1.16.1 is vulnerable to a novel type of the "ghost domain names" attack. The vulnerability works by targeting an Unbound instance. Unbound is queried for a subdomain of a rogue domain name. The rogue nameserver returns delegation… | ||
| CVE-2019-25040 | Hig | 0.42 | 7.5 | 0.02 | Apr 27, 2021 | Unbound before 1.9.5 allows an infinite loop via a compressed name in dname_pkt_copy. NOTE: The vendor disputes that this is a vulnerability. Although the code may be vulnerable, a running Unbound installation cannot be remotely or locally exploited | ||
| CVE-2019-25037 | Hig | 0.42 | 7.5 | 0.02 | Apr 27, 2021 | Unbound before 1.9.5 allows an assertion failure and denial of service in dname_pkt_copy via an invalid packet. NOTE: The vendor disputes that this is a vulnerability. Although the code may be vulnerable, a running Unbound installation cannot be remotely or locally exploited | ||
| CVE-2019-25036 | Hig | 0.42 | 7.5 | 0.02 | Apr 27, 2021 | Unbound before 1.9.5 allows an assertion failure and denial of service in synth_cname. NOTE: The vendor disputes that this is a vulnerability. Although the code may be vulnerable, a running Unbound installation cannot be remotely or locally exploited | ||
| CVE-2019-16866 | Hig | 0.42 | 7.5 | 0.04 | Oct 3, 2019 | Unbound before 1.9.4 accesses uninitialized memory, which allows remote attackers to trigger a crash via a crafted NOTIFY query. The source IP address of the query must match an access-control rule. | ||
| CVE-2019-25031 | Med | 0.38 | 5.9 | 0.01 | Apr 27, 2021 | Unbound before 1.9.5 allows configuration injection in create_unbound_ad_servers.sh upon a successful man-in-the-middle attack against a cleartext HTTP session. NOTE: The vendor does not consider this a vulnerability of the Unbound software. create_unbound_ad_servers.sh is a… | ||
| CVE-2025-11411 | Med | 0.37 | — | 0.00 | Oct 22, 2025 | NLnet Labs Unbound up to and including version 1.24.1 is vulnerable to possible domain hijack attacks. Promiscuous NS RRSets that complement positive DNS replies in the authority section can be used to trick resolvers to update their delegation information for the zone. Usually… | ||
| CVE-2020-28935 | Med | 0.36 | 5.5 | 0.00 | Dec 7, 2020 | NLnet Labs Unbound, up to and including version 1.12.0, and NLnet Labs NSD, up to and including version 4.3.3, contain a local vulnerability that would allow for a local symlink attack. When writing the PID file, Unbound and NSD create the file if it is not there, or open an… | ||
| CVE-2026-50248 | Med | 0.35 | 6.5 | 0.00 | Jul 22, 2026 | In NLnet Labs Unbound 1.7.0 up to and including 1.25.1, when an auth/rpz zone has a configured primary hostname that resolves to BOGUS A/AAAA, it is still considered as a possible XFR endpoint. A malicious actor that can spoof the hostname's A/AAAA record (no valid RRSIG… | ||
| CVE-2017-15105 | Med | 0.35 | 5.3 | 0.03 | Jan 23, 2018 | A flaw was found in the way unbound before 1.6.8 validated wildcard-synthesized NSEC records. An improperly validated wildcard NSEC record could be used to prove the non-existence (NXDOMAIN answer) of an existing wildcard record, or trick unbound into accepting a NODATA proof. | ||
| CVE-2026-56444 | Med | 0.31 | 5.9 | 0.00 | Jul 22, 2026 | In NLnet Labs Unbound 1.20.0 up to and including 1.25.1, when Unbound is configured with 'serve-expired: yes' and 'serve-expired-client-timeout > discard-timeout > 0' (contrary to the suggested values), the discard-timeout branch during the serve expired logic drops an aged… |
- risk 0.42cvss 7.5epss 0.00
In NLnet Labs Unbound 1.7.0 up to and including 1.25.1, insufficient validation of the RRSIG.Labels field combined with premature cache writes during RFC 8198 aggressive NSEC processing leads to cache poisoning that permits a malicious actor controlling a single delegated zone…
- risk 0.42cvss 7.5epss 0.00
In Unbound 1.9.0 up to and including 1.25.1, when a DNSCrypt query is received over TCP, the routine that encrypts the reply in place fails to bound the reply length against the destination buffer size. The size clamp that protects the UDP path is not applied on the TCP path, so…
- risk 0.42cvss 7.5epss 0.00
In NLnet Labs Unbound 1.22.0 up to and including 1.25.1, when downstream DNS-over-QUIC (DoQ) is enabled, the first two bidirectional streams on a new QUIC connection (stream_id 0 and 4) bypass the per-stream 'quic-size' gate entirely, and large input buffers are allocated later,…
- risk 0.42cvss 7.5epss 0.01
NLnet Labs Unbound up to and including version 1.25.0 has a denial of service vulnerability in the DNSSEC validator that can lead to a crash given malicious upstream replies. When Unbound constructs chase-reply messages for validation, the code uses the wrong counter to…
- risk 0.42cvss 7.5epss 0.01
NLnet Labs Unbound 1.14.0 up to and including version 1.25.0 has a vulnerability that results in heap overflow when encoding multiple NSID and/or DNS Cookie EDNS and/or EDNS Padding options in the reply packet. The relevant options ('nsid', 'answer-cookie', 'pad-responses'…
- risk 0.42cvss 7.5epss 0.01
NLnet Labs Unbound up to and including version 1.25.0 is vulnerable to a degradation of service attack related to parsing long lists of incoming EDNS options. An adversary sending queries with too many EDNS options can hold Unbound threads hostage while they are parsing and…
- risk 0.42cvss 7.5epss 0.00
NLnet Labs Unbound 1.16.2 up to and including version 1.25.0 has a vulnerability of the 'ghost domain names' family of attacks that could extend the ghost domain window by up to one cached TTL configured value. Similar to other 'ghost domain names' attacks, an adversary needs to…
- risk 0.42cvss 7.5epss 0.02
The DNS protocol in RFC 1035 and updates allows remote attackers to cause a denial of service (resource consumption) by arranging for DNS queries to be accumulated for seconds, such that responses are later sent in a pulsing burst (which can be considered traffic amplification…
- risk 0.42cvss 6.5epss 0.01
NLnet Labs Unbound, up to and including version 1.16.1, is vulnerable to a novel type of the "ghost domain names" attack. The vulnerability works by targeting an Unbound instance. Unbound is queried for a rogue domain name when the cached delegation information is about to…
- risk 0.42cvss 6.5epss 0.01
NLnet Labs Unbound, up to and including version 1.16.1 is vulnerable to a novel type of the "ghost domain names" attack. The vulnerability works by targeting an Unbound instance. Unbound is queried for a subdomain of a rogue domain name. The rogue nameserver returns delegation…
- risk 0.42cvss 7.5epss 0.02
Unbound before 1.9.5 allows an infinite loop via a compressed name in dname_pkt_copy. NOTE: The vendor disputes that this is a vulnerability. Although the code may be vulnerable, a running Unbound installation cannot be remotely or locally exploited
- risk 0.42cvss 7.5epss 0.02
Unbound before 1.9.5 allows an assertion failure and denial of service in dname_pkt_copy via an invalid packet. NOTE: The vendor disputes that this is a vulnerability. Although the code may be vulnerable, a running Unbound installation cannot be remotely or locally exploited
- risk 0.42cvss 7.5epss 0.02
Unbound before 1.9.5 allows an assertion failure and denial of service in synth_cname. NOTE: The vendor disputes that this is a vulnerability. Although the code may be vulnerable, a running Unbound installation cannot be remotely or locally exploited
- risk 0.42cvss 7.5epss 0.04
Unbound before 1.9.4 accesses uninitialized memory, which allows remote attackers to trigger a crash via a crafted NOTIFY query. The source IP address of the query must match an access-control rule.
- risk 0.38cvss 5.9epss 0.01
Unbound before 1.9.5 allows configuration injection in create_unbound_ad_servers.sh upon a successful man-in-the-middle attack against a cleartext HTTP session. NOTE: The vendor does not consider this a vulnerability of the Unbound software. create_unbound_ad_servers.sh is a…
- risk 0.37cvss —epss 0.00
NLnet Labs Unbound up to and including version 1.24.1 is vulnerable to possible domain hijack attacks. Promiscuous NS RRSets that complement positive DNS replies in the authority section can be used to trick resolvers to update their delegation information for the zone. Usually…
- risk 0.36cvss 5.5epss 0.00
NLnet Labs Unbound, up to and including version 1.12.0, and NLnet Labs NSD, up to and including version 4.3.3, contain a local vulnerability that would allow for a local symlink attack. When writing the PID file, Unbound and NSD create the file if it is not there, or open an…
- risk 0.35cvss 6.5epss 0.00
In NLnet Labs Unbound 1.7.0 up to and including 1.25.1, when an auth/rpz zone has a configured primary hostname that resolves to BOGUS A/AAAA, it is still considered as a possible XFR endpoint. A malicious actor that can spoof the hostname's A/AAAA record (no valid RRSIG…
- risk 0.35cvss 5.3epss 0.03
A flaw was found in the way unbound before 1.6.8 validated wildcard-synthesized NSEC records. An improperly validated wildcard NSEC record could be used to prove the non-existence (NXDOMAIN answer) of an existing wildcard record, or trick unbound into accepting a NODATA proof.
- risk 0.31cvss 5.9epss 0.00
In NLnet Labs Unbound 1.20.0 up to and including 1.25.1, when Unbound is configured with 'serve-expired: yes' and 'serve-expired-client-timeout > discard-timeout > 0' (contrary to the suggested values), the discard-timeout branch during the serve expired logic drops an aged…
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