CVE-2026-104431
High
Description
Zebra before 6.0.0 contains a denial of service vulnerability that allows unauthenticated peers to stall Tokio workers by submitting mempool transactions requiring expensive synchronous script verification. Attackers can send non-standard high-sigop P2SH transactions that reach CachedFfiTransaction::is_valid() before standardness checks, saturating the verifier buffer and rendering the node unresponsive.
SeverityHigh
CVSS7.5
Exploit probability—
ProductZcashfoundation Zebra
PublishedOct 2, 2026
First seenOct 2, 2026
Weakness typeCWE-405CWE-405
How to fix
Update
- ZcashFoundation zebra6.0.0 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| ZcashFoundation zebra | v < 6.0.0 | 6.0.0 |
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