Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:HCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.
Summary
CVE-2026-24401 is a medium-severity Uncontrolled Recursion (CWE-674) vulnerability in Avahi Avahi. Its CVSS base score is 6.5 (Medium).
Operationally, exploitation aligns with the MITRE ATT&CK technique Endpoint Denial of Service (T1499); ranked at the 17th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to SI-10 (Information Input Validation) and SC-5 (Denial-of-service Protection) — see the control section below for these in your framework.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-4603
Vulnerability Data
Avahi is a system which facilitates service discovery on a local network via the mDNS/DNS-SD protocol suite. In versions 0.9rc2 and below, avahi-daemon can be crashed via a segmentation fault by sending an unsolicited mDNS response containing a recursive CNAME…
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record, where the alias and canonical name point to the same domain (e.g., "h.local" as a CNAME for "h.local"). This causes unbounded recursion in the lookup_handle_cname function, leading to stack exhaustion. The vulnerability affects record browsers where AVAHI_LOOKUP_USE_MULTICAST is set explicitly, which includes record browsers created by resolvers used by nss-mdns. This issue is patched in commit 78eab31128479f06e30beb8c1cbf99dd921e2524.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Input validation can reject or constrain data that would otherwise drive unbounded recursive calls.
DoS protection mechanisms limit the resource-exhaustion impact of uncontrolled recursion without eliminating the flaw.
System monitoring can observe anomalous resource consumption that signals runaway recursion after it begins.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Secure SDLC practices directly prevent coding errors such as missing recursion limits or termination conditions.
Runtime monitoring of compute resources can detect excessive consumption caused by uncontrolled recursion.
Vulnerability identification processes can discover and record uncontrolled recursion flaws before deployment.
Capacity monitoring and resource provisioning can absorb or limit the impact of runaway recursion.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Security testing in development can detect excessive recursion via static analysis or fuzzing.
Secure development life cycle requires controls that prevent uncontrolled recursion through design and code review.
Application security requirements can mandate recursion limits or stack-depth checks.
Secure system architecture principles include resource-management and input-validation rules that limit recursion.
Secure coding standards directly prohibit or constrain recursive constructs that could exhaust stack or memory.
Capacity management includes monitoring and limits that mitigate resource exhaustion from runaway recursion.