Buffer overflow in Connman
CVE-2026-115863
ConnMan through 2.0 has a stack-based buffer overflow via a DHCPv6 Reply message. This occurs in get_domains in gdhcp/client.c. It copies a fixed NS_MAXDNAME (1025) bytes from a DHCPv6 DOMAIN_LIST (option 24) value into a 1026-byte stack buffer dns_name regardless of the actual option length, then walks DNS labels with an unbounded "c += jump + 1" loop. A crafted DHCPv6 REPLY with a DOMAIN_LIST option of >= 1025 non-zero bytes makes the label walk leave the buffer and read/write '.' past its end in attacker-chosen strides. An on-link attacker can trigger this without authentication via a forged Router Advertisement (O=1) and a forged DHCPv6 REPLY matching xid/CLIENTID with a long DOMAIN_LIST. The impact is unauthenticated on-link crash of connmand (runs as root). This was introduced in bb06c47.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.6 (High). Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
Frequently asked questions
- What is CVE-2026-115863?
- CVE-2026-115863 is a high-severity vulnerability in Connman, classified under Stack-based Buffer Overflow. CVSS score: 7.6/10. Published 2026-10-23.
- How severe is CVE-2026-115863?
- High severity. CVSS v3 base score is 7.6 out of 10.