CVE-2026-109366

MEDIUM
MEDIUM Priority: 0.01 BB Relevance: 73/100
Published: 2026-10-12 Modified: 2026-10-26 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
AT: Present
VC: None
VI: None
VA: Low

Description

Zebra before 6.4.0 contains an improper integrity validation vulnerability in the inbound gossip download path that allows unauthenticated peers to force dropping of new blocks without penalty. Attackers can serve a real block with a coinbase scriptSig rewritten to height 1, which keeps the ZIP-244 block hash, triggering a behind-tip drop before consensus validation and delaying tip discovery for mining backends.

Weakness Classification (1)

Bug Bounty Relevance

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

CVSS Score

6.3 / 10.0 v4.0
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

EPSS — Exploitation Probability

0.16%
Raw Score 0.001570
Percentile 4.8%
Date 2026-10-29

EPSS Trend

2026-10-29
0.00157
2026-10-28
0.00157

Intelligence Sources

mitre ref →
nvd ref →