VulnerabilityPublished 15 Mar 2023Updated 3 Nov 2025

CVE-2023-28450: Dnsmasq

Source CVE Database V5

Not known to be exploited · CVSS 7.5 High · fixed in 2.90 : patch Dnsmasq soon.

Data as of 26 Oct 2026, 14:05 UTC

CVSS 3.1 base score

7.5High

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 1.8% chance of exploitation in 30 days – higher than 78% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Affects: Dnsmasq before 2.90
Patch: Available – fixed in 2.90

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: None
Availability: High

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 15 Mar 2023
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

AI-suggested

Upgrade all Dnsmasq instances to version 2.90 or later, which corrects the default EDNS0 UDP packet size setting to 1232 bytes.
Audit network devices and servers to identify any running vulnerable Dnsmasq versions and prioritize patching.
Configure DNS servers and firewalls to monitor and limit oversized UDP DNS packets, applying rate limiting to mitigate potential abuse.
Implement DNS response size controls and consider fallback to TCP for large DNS responses to avoid fragmentation issues.
Regularly monitor DNS traffic for anomalies that may indicate exploitation attempts or denial of service activities.
Educate network and security teams about the vulnerability and ensure incident response plans include DNS service disruption scenarios.
For critical infrastructure, consider deploying redundant DNS servers with patched software to ensure high availability.
Engage with upstream DNS providers and ISPs to ensure they are also protected against this vulnerability to reduce exposure.

Description

An issue was discovered in Dnsmasq before 2.90. The default maximum EDNS.0 UDP packet size was set to 4096 but should be 1232 because of DNS Flag Day 2020.

Impact

For European organizations, this vulnerability can lead to DNS service disruptions, impacting internal and external network communications. DNS outages can cause widespread application failures, loss of internet connectivity, and degraded user experience. Critical sectors such as finance, healthcare, telecommunications, and government services that rely heavily on stable DNS infrastructure could face operational interruptions. The disruption of DNS resolution may also affect cloud services and remote work capabilities, which are prevalent in Europe. Since the vulnerability can be exploited remotely without authentication, attackers could launch denial of service attacks against vulnerable DNS servers, potentially amplifying the impact. The availability impact could cascade into broader network outages, affecting business continuity and causing financial and reputational damage. European organizations with complex network environments using Dnsmasq as part of their DNS infrastructure are particularly at risk. Additionally, the vulnerability could be leveraged in multi-stage attacks where DNS disruption is used as a diversion or to degrade defenses.

References

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