CVE-2026-12725
MediumCVSS 5.9Exploitation Probability (EPSS)
Low risk42th percentile - higher than 42% of all known CVEs
Summary
A heap-based buffer overflow was found in dnsmasq. When DNSSEC validation and query logging are both enabled, logging of DS or DNSKEY replies containing unsupported algorithm or digest types can cause dnsmasq to write past the end of an internal logging buffer. A remote attacker able to supply such a DNS response may crash the dnsmasq process, resulting in denial of service.
Risk Assessment
The risk is that a remote attacker can crash the DNS server without authentication, causing denial of service for name resolution services in the organization. The attack is triggered by sending a crafted DNS response.
Recommendation
Immediately update dnsmasq to the latest patched version. As a temporary workaround, disable DNSSEC validation or query logging if they are not essential.
Other vulnerabilities in dnsmasq
See all- CVE-2017-14496High
An integer underflow in the add_pseudoheader function in dnsmasq before version 2.78 allows remote attackers to cause a denial of service via a crafted DNS request when the --add-mac, --add-cpe-id, or --add-subnet option is specified.
- CVE-2017-14495High
A memory leak in dnsmasq before version 2.78 occurs when the --add-mac, --add-cpe-id, or --add-subnet option is specified. This allows remote attackers to cause a denial of service through DNS response creation manipulation.
- CVE-2017-13704High
In dnsmasq before version 2.78, if the DNS packet size does not match the expected size, the size parameter in a memset call gets a negative value. As it is an unsigned value, memset ends up writing up to 0xffffffff zeros, causing dnsmasq to crash.
- CVE-2015-8899High
Dnsmasq before 2.76 allows remote servers to cause a denial of service (crash) via a reply with an empty DNS address that has an (1) A or (2) AAAA record defined locally.
- CVE-2026-4891Medium
A heap-based out-of-bounds read vulnerability in the DNSSEC validation of dnsmasq allows remote attackers to cause a denial of service via a crafted DNS packet.
- CVE-2026-4890High
The DNSSEC validation in dnsmasq has a denial of service (DoS) vulnerability. A remote attacker can send a crafted DNS packet, causing the service to crash.
- CVE-2017-14491Critical
Heap-based buffer overflow in dnsmasq before 2.78 allows remote attackers to cause a denial of service (crash) or execute arbitrary code via a crafted DNS response.
- CVE-2017-14493Critical
A stack-based buffer overflow in dnsmasq before version 2.78 allows remote attackers to cause a denial of service (crash) or execute arbitrary code via a crafted DHCPv6 request.
- CVE-2017-14492Critical
Heap-based buffer overflow in dnsmasq before version 2.78 allows remote attackers to cause a denial of service (crash) or execute arbitrary code via a crafted IPv6 router advertisement request.
- CVE-2026-13002Medium
A flow in the dnssec.c library causes an infinite loop in the dnsmasq service. An attacker who controls any DNSSEC-signed zone can hang the dnsmasq process with a single crafted response, killing all DNS resolution for its clients.
Original NVD description (English source)
A heap-based buffer overflow was found in dnsmasq. When DNSSEC validation and query logging are both enabled, logging of DS or DNSKEY replies containing unsupported algorithm or digest types can cause dnsmasq to write past the end of an internal logging buffer. A remote attacker able to supply such a DNS response may crash the dnsmasq process, resulting in denial of service.