CVE-2026-1678

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.

CVSS 3.1

9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS

0.4% chance of exploitation in the next 30 days; higher than 33% of CVEs (scores of 2026-10-25)

CWE

CWE-787

Published

2026-03-05

Modified

2026-10-15

Record from

the NVD, synced 2026-10-19

Affected

• zephyrproject:zephyr

References

• https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-536f-h63g-hj42
• https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-536f-h63g-hj42

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