CVE-2026-1678 dns: memory‑safety issue in the DNS name parser
A malicious DNS response can cause an out-of-bounds write in Zephyr RTOS, potentially leading to code execution or denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-1678?
CVE-2026-1678 is a critical memory corruption vulnerability in Zephyrproject Zephyr, published on 5 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
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.
Weakness: CWE-787
Which versions are affected by CVE-2026-1678?
It affects 1 product.
Products include Zephyrproject Zephyr.
How do I fix CVE-2026-1678?
No fix has been published for CVE-2026-1678 yet. Limit exposure of the affected software until one is available.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-1678 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-1678 exists.
Other vulnerabilities in Zephyrproject Zephyr
- CVE-2026-5067 Out-of-bounds read/write in HTTP WebSocket upgrade via non-null-terminated Sec-WebSocket-Key
- CVE-2022-3806 Bluetooth HCI Error Handling Double Free
- CVE-2017-14199 Memory corruption in getaddrinfo
- CVE-2018-1000800 Null dereference in n/a
- CVE-2021-3329 DOS: Incorrect handling of the initial HCI ACL_MTU handshake packet leads to crash of bluetooth host layer
Sources
Also known as GHSA-536f-h63g-hj42.