CVE-2026-104426

Zebra before 6.1.0 Quadratic Complexity DoS via Block Transparent Value Check

8.2 High

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.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: High
Privileges needed: None
User interaction: None

What an attacker can affect

Confidentiality: None
Integrity: None
Availability: High

Exploit likelihood

0.31%Unchanged since Oct 3, 2026

What each source reports

CVE List Score used 8.2

Zebra before 6.1.0 Quadratic Complexity DoS via Block Transparent Value Check

Record: CVE-2026-104426
CVSS 4.0: 8.2 HighCVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
CVSS 3.1: 5.9 MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness: CWE-407
Updated: 2026-11-02

EUVDEUVD-2026-91437 8.2

Record: EUVD-2026-91437
CVSS 4.0: 8.2 HighCVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Updated: 2026-11-02

GitHub AdvisoriesGHSA-g338-vc6m-x872 8.2

Zebra before 6.1.0 contains an inefficient algorithmic complexity vulnerability in...

Record: GHSA-g338-vc6m-x872
CVSS 4.0: 8.2 HighCVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS 3.1: 5.9 MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness: CWE-407
Updated: 2026-11-02

NVD 8.2

Record: CVE-2026-104426
CVSS 4.0: 8.2 HighCVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS 3.1: 5.9 MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness: CWE-407
Updated: 2026-11-02

OSV 8.2

Zebra before 6.1.0 Quadratic Complexity DoS via Block Transparent Value Check

Record: CVE-2026-104426
CVSS 4.0: 8.2 HighCVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Weakness: CWE-407
Updated: 2026-11-02

Affected products

zcashfoundation zebra

History

History
Recorded	Changed	Sources
Nov 2, 2026	first indexed	CVE List, EUVD, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2026-104426 is a high vulnerability (CVSS 8.2) in Zcashfoundation Zebra, published October 2, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.31%, the 23rd percentile. No source names a fixed version.