CVE-2026-115863

HIGH

MEDIUM Priority: 0.02 BB Relevance: 60/100

Published: 2026-10-23 Modified: 2026-10-23 First seen: 2026-10-29 Status: active

Attack Surface

Adjacent Low Complexity No Auth No Interaction

CVSS Vector Breakdown

AV: Adjacent

AC: Low

PR: None

UI: None

S: Unchanged

C: Low

I: Low

A: High

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.