CVE-2026-104432 Zebra before 6.3.0 False Readiness via Discarded One-Hash FindBlocks Response
Attackers can cause Zebra nodes to falsely report readiness, bypassing health checks while remaining unsynchronized with the blockchain tip.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-104432?
CVE-2026-104432 is a medium-severity vulnerability in ZcashFoundation zebra, published on 2 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Zebra before 6.3.0 contains an improper exceptional condition check in ChainSync::obtain_tips that discards valid one-hash FindBlocks responses, falsely reporting close-to-tip status. Peers returning only the next block hash cause a zero-length sync sample, making the /ready endpoint return 200 OK while the node remains behind the tip.
Weakness: CWE-754
Which versions are affected by CVE-2026-104432?
How do I fix CVE-2026-104432?
No fix has been published for CVE-2026-104432 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-104432 being exploited?
There is no known exploitation of CVE-2026-104432 in the wild and no public exploit code.
Sources
Also known as GHSA-h8m8-844p-v3m9, GHSA-x44x-7hf5-cfvh.