CVE-2026-104425 Zebra before 6.1.0 Batch-Verification Poisoning DoS via Unattributed Pushed Transactions
Unauthenticated attackers can degrade Zcash node performance by pushing invalid transactions, causing significant block processing delays.
- 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-2026-104425?
CVE-2026-104425 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
ZcashFoundation Zebra before 6.1.0 contains a resource exhaustion vulnerability that allows unauthenticated peers to degrade block processing by pushing transactions with invalid Orchard proofs without being misbehavior-scored. Attackers can repeatedly push invalid proofs into the shared halo2 batch verifier, forcing honest block proofs onto the slow individual-verification path and slowing block processing roughly sevenfold.
Weakness: CWE-405
Which versions are affected by CVE-2026-104425?
How do I fix CVE-2026-104425?
No fix has been published for CVE-2026-104425 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-2026-104425 being exploited?
There is no known exploitation of CVE-2026-104425 in the wild and no public exploit code.
Sources
Also known as GHSA-2gfx-528v-grp3, GHSA-g7c4-2w6c-cr3r.