What is CVE-2026-5856?

CVE-2026-5856 is a high-severity vulnerability in Contiki-ng, classified under Out-of-bounds Read. CVSS score: 7.1/10. Published 2026-08-06.

How severe is CVE-2026-5856?

High severity. CVSS v3 base score is 7.1 out of 10.

Out-of-bounds Read in Contiki-ng

CVE-2026-5856

Contiki-NG's DNS/mDNS resolver skip_name() in os/services/resolv/resolv.c walks DNS wire-format name labels with no packet-boundary check, and the caller in newdata() invokes it in a loop iterating nquestions times from the attacker-contro…

Vulnerability class: Buffer Overflow

CVSS v3 metric

CVSS v3 base score 7.1 (High). Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:L.

Affected products

Contiki-ng — versions 0

Weakness classification (CWE)

CWE-125 — Out-of-bounds Read

References

disclosure@vulncheck.com (product)
disclosure@vulncheck.com (patch)
disclosure@vulncheck.com (issue-tracking)

Frequently asked questions

What is CVE-2026-5856?: CVE-2026-5856 is a high-severity vulnerability in Contiki-ng, classified under Out-of-bounds Read. CVSS score: 7.1/10. Published 2026-08-06.
How severe is CVE-2026-5856?: High severity. CVSS v3 base score is 7.1 out of 10.