Zebra before 6.1.0 Incorrect Block Size Calculation in getblocktemplate
Summary
| CVE | CVE-2026-104424 |
|---|---|
| State | PUBLISHED |
| Assigner | VulnCheck |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-10-02 12:17:12 UTC |
| Updated | 2026-10-06 03:17:00 UTC |
| Description | Zebra before 6.1.0 contains an incorrect calculation vulnerability in its ZIP-317 block template selector that omits header and transaction-count size from the block budget. Attackers can place valid selectable transactions in a victim miner's mempool to shape templates into oversized blocks, causing rejection and wasted proof-of-work. |
Risk And Classification
Primary CVSS: v4.0 6.3 MEDIUM from [email protected]
CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/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
EPSS: 0.002730000 probability, percentile 0.179810000 (date 2026-10-06)
Problem Types: CWE-131 | CWE-131 Incorrect Calculation of Buffer Size
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | [email protected] | Secondary | 6.3 | MEDIUM | CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/C... |
| 4.0 | CNA | CVSS | 6.3 | MEDIUM | CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N |
| 3.1 | [email protected] | Secondary | 3.7 | LOW | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L |
| 3.1 | CNA | CVSS | 3.7 | LOW | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L |
CVSS v4.0 Breakdown
Attack Vector
NetworkAttack Complexity
HighAttack Requirements
PresentPrivileges Required
NoneUser Interaction
NoneConfidentiality
NoneIntegrity
NoneAvailability
LowSub Conf.
NoneSub Integrity
NoneSub Availability
NoneCVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/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 v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
HighPrivileges Required
NoneUser Interaction
NoneScope
UnchangedConfidentiality
NoneIntegrity
NoneAvailability
LowCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | ZcashFoundation | Zebra | affected 6.1.0 semver | Not specified |
| CNA | ZcashFoundation | Zebra | unaffected 6.1.0 semver | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| github.com/ZcashFoundation/zebra/security/advisories/GHSA-95m2-vx53-v2jw | [email protected] | github.com | |
| www.vulncheck.com/advisories/zebra-before-6.1.0-incorrect-block-size-calculatio... | [email protected] | www.vulncheck.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: ebfull (en)
CNA: upbqdn (en)
There are currently no legacy QID mappings associated with this CVE.