Quick answers
- Is CVE-2026-104428 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-104428 being exploited in the wild.
- How severe is CVE-2026-104428?
- Medium severity, with a CVSS score of 5.3, published 2 October 2026.
- Which products and versions are affected?
- Zcash Foundation Zebra before 11.0.0.
- Is there a fix for CVE-2026-104428?
- Yes: fixed in 11.0.0. Until then: Keep RPC cookie authentication enabled and restrict the RPC port to trusted networks only. Note that this does not protect against calls forwarded through lightwalletd, which relays the getblock method; upgrading to the patched version is the durable fix. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-104428 attacked?
- It is attacked over the network.
- Am I affected by CVE-2026-104428?
- Check whether you run Zcash Foundation Zebra at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
How to fix
- Fixed in: 11.0.0
Keep RPC cookie authentication enabled and restrict the RPC port to trusted networks only. Note that this does not protect against calls forwarded through lightwalletd, which relays the getblock method; upgrading to the patched version is the durable fix.
Technical details
The getblock RPC method with verbosity level 2 attempts to convert a confirmations value from i64 to u32 using .expect(), which panics when the value is -1 (the sentinel for blocks not on the best chain). Because the Zebra workspace sets panic = "abort", the panic terminates the entire node process. An unauthenticated remote attacker can trigger this by calling getblock with a side-chain block hash and verbosity 2, then repeat the call to maintain a denial of service.
Affected products
- Zcash Foundation Zebra before 11.0.0
Timeline
- 2026-07-03: disclosed
- 2026-10-02: advisory