Buffer overflow in Contiki-ng
CVE-2026-5857
Contiki-NG's MQTT client parse_publish_vhdr() in os/net/app-layer/mqtt/mqtt.c sets topic_len_received=1 before checking topic_len against the 64-byte limit, so an over-length topic returns early but leaves the flag set. On the next TCP seg…
Vulnerability class: Buffer Overflow
CVSS v3 metric
CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H.
Affected products
- Contiki-ng — versions 0
Weakness classification (CWE)
References
- disclosure@vulncheck.com (product)
- disclosure@vulncheck.com (patch)
- disclosure@vulncheck.com (issue-tracking)
Frequently asked questions
- What is CVE-2026-5857?
- CVE-2026-5857 is a high-severity vulnerability in Contiki-ng, classified under Out-of-bounds Write. CVSS score: 8.1/10. Published 2026-08-06.
- How severe is CVE-2026-5857?
- High severity. CVSS v3 base score is 8.1 out of 10.