CVE-2026-26018
Published: 06 March 2026
Summary
CVE-2026-26018 is a high-severity PRNG (CWE-337) vulnerability in Coredns.Io Coredns. Its CVSS base score is 7.5 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 7.1th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
Threat & Defense at a Glance
Threat & Defense Details
Likely Mitigating ControlsAI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Limiting concurrent sessions directly prevents uncontrolled resource consumption by capping the number of active sessions per user or account.
Contingency plan testing includes resource exhaustion scenarios to verify recovery, making it harder for attackers to sustain exploits that cause uncontrolled consumption.
Updated contingency plans include current procedures to detect, contain, and recover from resource exhaustion, limiting an attacker's ability to sustain impact from uncontrolled consumption.
Alternate site allows resumption of operations if resource exhaustion at the primary site is exploited to cause unavailability.
Alternate telecommunications services enable resumption of essential functions when primary services become unavailable due to uncontrolled resource consumption.
Planning and coordination of security activities (scans, tests, maintenance) directly imposes scheduling and throttling that prevents those activities from producing uncontrolled resource consumption.
Performance metrics and monitoring inherently track resource consumption patterns, making uncontrolled consumption easier to detect and mitigate.
Terminating idle connections bounds resource consumption that would otherwise allow uncontrolled accumulation of open sessions.
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Remote unauthenticated crash of CoreDNS (public-facing DNS server) via crafted queries directly enables T1190 (Exploit Public-Facing Application) for initial access/impact and T1499.004 (Application or System Exploitation) to achieve denial of service.
NVD Description
CoreDNS is a DNS server that chains plugins. Prior to version 1.14.2, a denial of service vulnerability exists in CoreDNS's loop detection plugin that allows an attacker to crash the DNS server by sending specially crafted DNS queries. The vulnerability…
more
stems from the use of a predictable pseudo-random number generator (PRNG) for generating a secret query name, combined with a fatal error handler that terminates the entire process. This issue has been patched in version 1.14.2.
Deeper analysisAI
CVE-2026-26018 is a denial-of-service vulnerability affecting CoreDNS, a DNS server that chains plugins, in versions prior to 1.14.2. The flaw resides in the loop detection plugin, where a predictable pseudo-random number generator (PRNG) is used to generate a secret query name. When combined with a fatal error handler that terminates the entire process, specially crafted DNS queries can trigger a crash of the DNS server.
Any unauthenticated attacker with network access to the CoreDNS instance can exploit this vulnerability with low attack complexity and no user interaction required, as reflected in its CVSS v3.1 base score of 7.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H). Exploitation leads to a high-impact denial of service by fully terminating the server process, disrupting DNS resolution services.
CoreDNS has patched this issue in version 1.14.2. Administrators should upgrade to this version or later to mitigate the vulnerability. Additional details are available in the CoreDNS release notes at https://github.com/coredns/coredns/releases/tag/v1.14.2 and the GitHub security advisory at https://github.com/coredns/coredns/security/advisories/GHSA-h75p-j8xm-m278.
Details
- CWE(s)