What’s Vulnerable › Vulnerabilities

CVE-2026-1678: dns: memory‑safety issue in the DNS name parser

• Severity: critical (CVSS 9.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2026-03-05 · updated 2026-10-15
• Weakness: CWE-787

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.

Affected products

• zephyrproject zephyr: through 4.3.0

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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