CVE-2026-1678
dns: memory‑safety issue in the DNS name parser
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.
INFO
Published Date :
March 5, 2026, 7:16 a.m.
Last Modified :
March 9, 2026, 6:33 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | CRITICAL | e2e69745-5e70-4e92-8431-deb5529a81ad | ||||
| CVSS 3.1 | CRITICAL | [email protected] | ||||
| CVSS 3.1 | CRITICAL | [email protected] |
Solution
- Update the dns_unpack_name() function to correctly manage buffer tailroom.
- Ensure DNS label appending logic accounts for buffer growth accurately.
- Test thoroughly with various DNS response sizes.
- Enable assertions in debug builds for early detection.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-1678.
| URL | Resource |
|---|---|
| https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-536f-h63g-hj42 | Exploit Patch Vendor Advisory |
| https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-536f-h63g-hj42 | Exploit Patch Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-1678 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-1678
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-1678 vulnerability anywhere in the article.
-
Daily CyberSecurity
Critical 9.4 CVSS Zephyr RTOS Flaw Exposes Millions of IoT Devices to RCE
Security researchers have disclosed a critical memory-safety vulnerability in the Zephyr Project, a high-profile, scalable real-time operating system (RTOS) designed for resource-constrained IoT devic ... Read more
The following table lists the changes that have been made to the
CVE-2026-1678 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Mar. 09, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Added CPE Configuration OR *cpe:2.3:o:zephyrproject:zephyr:*:*:*:*:*:*:*:* versions up to (including) 4.3.0 Added Reference Type CISA-ADP: https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-536f-h63g-hj42 Types: Exploit, Patch, Vendor Advisory Added Reference Type Zephyr Project: https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-536f-h63g-hj42 Types: Exploit, Patch, Vendor Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Mar. 05, 2026
Action Type Old Value New Value Added Reference https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-536f-h63g-hj42 -
New CVE Received by [email protected]
Mar. 05, 2026
Action Type Old Value New Value Added 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. Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:H Added CWE CWE-787 Added Reference https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-536f-h63g-hj42