Cyber Resilience

CVE-2026-12245

High

Published: 25 June 2026

Published
25 June 2026
Modified
26 June 2026
KEV Added
—
Patch
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CVSS Score v4 8.7 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0027 19.2th percentile
Risk Priority 55 floored blend · peak EPSS

Summary

CVE-2026-12245 is a high-severity Use After Free (CWE-416) vulnerability in Nlnetlabs Nsd. Its CVSS base score is 8.7 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Application or System Exploitation (T1499.004); ranked at the 19.2th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

NSD from version 4.13.0 has a heap use-after-free bug in logging errors on TLS connections, causing a crash of the server process, which can be triggered trivially by sending a DNS query over a DoT connection, and closing the connection…

more

without reading the response.

CWE(s)
CWE-416

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1499.004 Application or System Exploitation Impact
Adversaries may exploit software vulnerabilities that can cause an application or system to crash and deny availability to users.
attack.mitre.org →
Why these techniques?

Use-after-free in NSD DoT logging directly enables application exploitation to crash the DNS server process (T1499.004).

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

Affected Assets

nlnetlabs
nsd
4.13.0 — 4.14.3

Mitigating Controls

Likely Mitigating Controls AI

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.

SI-16 Memory Protection
addresses: CWE-416

Use-after-free exploits that achieve arbitrary code execution are blocked or significantly hardened by non-executable pages and ASLR.

References