Vulnerability · Published Oct 2, 2026 · Assigned by VulnCheck

CVE-2026-104426Zebra before 6.1.0 Quadratic Complexity DoS via Block Transparent Value Check

Medium 5.9

In plain English

A medium-severity security flaw in zebra from ZcashFoundation. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 24% of all known vulnerabilities).

Severity (CVSS 3.1)5.9Medium

Exploit odds (30 days)0.3%top 76.3% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

Zebra before 6.1.0 contains an inefficient algorithmic complexity vulnerability in remaining_transaction_value that clones the entire block-level spent-UTXO map per transaction during contextual verification. Attackers can mine or seed the mempool with roughly 26,000 minimal single-input transactions in one block, stalling every validating node for over 52 seconds.

Affected products (as reported)

Vendor	Product	Versions
ZcashFoundation	zebra	0 – before 6.1.0

Weakness: CWE-407 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

References

GitHub Security Advisory (GHSA-4g24-549m-hp75) vendor-advisory
VulnCheck Advisory: Zebra before 6.1.0 Quadratic Complexity DoS via Block Transparent Value Check third-party-advisory