CVE-2026-1678 json
dns: memory‑safety issue in the DNS name parser
published 2026-03-05 8 mo ago modified 2026-11-05 3 d ago also EUVD-2026-9792
- cvss
- 9.4
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.4%
- EPSS 0.4% chance of exploitation in 30 days, percentile 38%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- zephyrproject zephyr 3.7.2, 4.2.2, 4.3.1
CISA SSVC
- Exploitation
- Proof of concept is public
- Automatable
- yes
- Technical impact
- total
- Assessed
- 8 mo ago
Exploit prediction
0.44% chance of exploitation in the next 30 days, higher than 38% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- github.com https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-536f-h63g-hj42 referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 9.4 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:H |
| NVD | 3.1 | 9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
Affected products
- zephyrproject-rtos Zephyr
Classification
- Weakness
-
- CWE-787 Out-of-bounds Write
References
-
github.com
/zephyrproject-rtos/zephyr/security/advisories/GHSA-536f-h63g-hj42
exploit, patch, vendor-advisory
Sources
- CVE List CVE-2026-1678
- NVD CVE-2026-1678
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