CVE-2026-109364: Zebra 2.3.0 before 6.4.0 Peer Ban Bypass via Exact-IP Keying

Severity: medium (CVSS 5.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-10-12 · updated 2026-10-15
Weakness: CWE-693

Description

Zebra 2.3.0 before 6.4.0 contains a protection mechanism failure that allows unauthenticated peers to evade bans because bans and misbehavior scores are keyed on exact IP addresses. Attackers can reconnect from fresh IPv6 addresses in their /64 allocation or flush the 20,000-entry FIFO ban list to restore access for banned peers.

Affected products

ZcashFoundation zebra: from 2.3.0 before 6.4.0 — fixed in 6.4.0

How to fix

Upgrade to a fixed version: ZcashFoundation zebra 6.4.0. Check the vendor advisory for mitigations.

References

https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-jhpp-8h75-7pv5
https://www.vulncheck.com/advisories/zebra-2.3.0-before-6.4.0-peer-ban-bypass-via-exact-ip-keying

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