CVE-2026-55606

MEDIUM
MEDIUM Priority: 0.02 BB Relevance: 73/100
Published: 2026-10-23 Modified: 2026-10-29 First seen: 2026-10-29 Status: active

Attack Surface

Network Low Complexity No Auth No Interaction

CVSS Vector Breakdown

AV: Network
AC: Low
PR: None
UI: None
S: Unchanged
C: Low
I: None
A: Low

Description

odhcpd is the DHCPv6, DHCPv4, and router-advertisement server used by OpenWrt. In versions 25.12 and prior, odhcpd's DHCPv6 self-loop detection at dhcpv6.c:720 uses a network-byte-order DUID length value directly as the memcmp() size parameter. On little-endian hosts, this causes memcmp() to read far beyond the stack buffer — a single unauthenticated DHCPv6 packet triggers a 2560-byte overread from a 128-byte buffer. At time of publication, there are no publicly available patches.

Weakness Classification (1)

Affected Software (1)

VendorProductVersion
openwrt odhcpd <= 25.12

Bug Bounty Relevance

73 / 100
✓ Network accessible
✓ No authentication
✓ Low complexity
✓ No user interaction

CVSS Score

6.5 / 10.0 v3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L

EPSS — Exploitation Probability

0.38%
Raw Score 0.003790
Percentile 31.9%
Date 2026-10-29

EPSS Trend

2026-10-29
0.00379
2026-10-28
0.00379

Intelligence Sources

mitre ref →
nvd ref →