CVE-2026-104428 Zebra before 11.0.0 Denial of Service via getblock Verbosity 2
Remote attackers can crash Zebra nodes by sending specific RPC requests, causing a denial of service for the Zcash network.
- 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-2026-104428?
CVE-2026-104428 is a medium-severity denial of service 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
The getblock RPC method in zebra-rpc before 11.0.0, used by the Zcash Foundation's Zebra node, panics on verbosity 2 for a side-chain block because the block's -1 confirmations sentinel is converted to u32 with .expect(), aborting the process. Remote unauthenticated attackers, directly or through lightwalletd, can repeat this call to keep the node in a crash loop.
Weakness: CWE-617
Which versions are affected by CVE-2026-104428?
How do I fix CVE-2026-104428?
No fix has been published for CVE-2026-104428 yet. Limit exposure of the affected software until one is available.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-104428 being exploited?
There is no known exploitation of CVE-2026-104428 in the wild and no public exploit code.
Sources
Also known as GHSA-2qvh-q2cj-955r, GHSA-x6v8-c2xp-928m.