Vulnerability Description
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.
CVSS Score
HIGH
Related Weaknesses (CWE)
References
- https://git.kernel.org/pub/scm/network/connman/connman.git/commit/?id=bb06c47101
- https://git.kernel.org/pub/scm/network/connman/connman.git/tree/gdhcp/client.c
- https://lore.kernel.org/connman/[email protected]/
FAQ
What is CVE-2026-115863?
CVE-2026-115863 is a vulnerability with a CVSS score of 7.6 (HIGH). 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 (op...
How severe is CVE-2026-115863?
CVE-2026-115863 has been rated HIGH with a CVSS base score of 7.6/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-115863?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.