Zebra before 7.0.0 Denial of Service via Quadratic Sighash Computation

Advisories

Zebra before 7.0.0 Denial of Service via Quadratic Sighash Computation

Severity: high
Date: 11/7/2026
Affecting: zebra >= 0, < 7.0.0
CVE: CVE-2026-123559
CWE: CWE-407 Inefficient Algorithmic Complexity
CVSS: 8.7
CVSS V4 Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
References: GitHub Security Advisory (GHSA-j4cw-58mj-7w6v)
Credit: asafmod, mpguerra, conradoplg, upbqdn
Description: Zebra before 7.0.0 contains an inefficient algorithmic complexity vulnerability that allows unauthenticated peers to exhaust verification threads by submitting transactions with many transparent inputs. Attackers can relay invalid transactions with tens of thousands of inputs, forcing quadratic ZIP-244 or ZIP-243 digest recomputation that stalls Rayon-backed block verification for minutes.

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