🔐 CVE Alert

CVE-2026-1678

CRITICAL 9.4

dns: memory‑safety issue in the DNS name parser

CVSS Score
9.4
EPSS Score
0.0%
EPSS Percentile
0th

dns_unpack_name() caches the buffer tailroom once and reuses it while appending DNS labels. As the buffer grows, the cached size becomes incorrect, and the final null terminator can be written past the buffer. With assertions disabled (default), a malicious DNS response can trigger an out-of-bounds write when CONFIG_DNS_RESOLVER is enabled.

CWE CWE-787
Vendor zephyrproject-rtos
Product zephyr
Published Mar 5, 2026
Last Updated Mar 5, 2026
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CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:H
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
High
Availability
High

Affected Versions

zephyrproject-rtos / Zephyr
* ≤ 4.3

References

NVD ↗ CVE.org ↗ EPSS Data ↗
github.com: https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-536f-h63g-hj42