CVE-2026-104426

Zebra before 6.1.0 Quadratic Complexity DoS via Block Transparent Value Check

MEDIUM
5.9
CVSS Score
Published: October 2, 2026 at 11:38 AM UTC
Updated: October 2, 2026 at 05:59 PM UTC
2 products affected across 2 vendorsZebraZebra

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Severity
MEDIUM5.9
Exploit prediction
EPSS 0.3%
SSVC
No known exploit

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

95%
v < 6.1.0
Affected range stops below 6.1.0, so it looks safe — our inference, not a vendor statement
v < 6.1.0
Vendor states this is fixed in 6.1.0 (unaffected)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

5.9MEDIUMVulnCheck
Attack Vector
NETWORK
Complexity
HIGH
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-407

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