CVE-2026-104435 Zebra 4.4.0 Consensus Divergence via V5 SIGHASH_SINGLE Without Output
Attackers can cause network consensus splits by broadcasting crafted transactions that Zebra accepts but other nodes reject, leading to potential denial of service.
- 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-2026-104435?
CVE-2026-104435 is a high-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 zebrad 4.4.0 and zebra-script 6.0.0 fail to enforce a ZIP-244 consensus rule, accepting V5 transparent inputs signed with SIGHASH_SINGLE that lack a corresponding output. Attackers can broadcast crafted V5 transactions with more inputs than outputs that Zebra accepts but zcashd rejects, causing a network consensus split.
Weakness: CWE-347
Which versions are affected by CVE-2026-104435?
4 open source packages ship an affected version, including zebra-script and zebrad.
| Package | Affected | Fixed in |
|---|---|---|
zebra-script crates.io | All versions | 6.0.1 |
zebra-script crates.io | All versions | 6.0.1 |
zebrad crates.io | All versions | 4.4.1 |
zebrad crates.io | All versions | 4.4.1 |
How do I fix CVE-2026-104435?
Upgrade zebra-script to 6.0.1 or later.
Is CVE-2026-104435 being exploited?
There is no known exploitation of CVE-2026-104435 in the wild and no public exploit code.
Sources
Also known as GHSA-gm38-j348-x4mq, GHSA-pvmv-cwg8-v6c8.