Zebra before 4.5.0 contains an uncontrolled resource consumption vulnerability that allows remote P2P peers to exhaust blocking-pool threads by sending oversized block locator vectors. Attackers can send getblocks or getheaders messages with up to 65,535 locator hashes, triggering per-hash chain lookups that degrade block validation, RPC, and mempool performance.

Attack Vector Network

Attack Complexity High

Privileges Required None

Attack Requirements Present

User Interaction None

Vulnerable System Confidentiality Impact None

Vulnerable System Integrity Impact None

Vulnerable System Availability Impact Low

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

Attack Vector Network

Attack Complexity High

Privileges Required None

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact Low

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Exploitation none

Automatable no

Technical Impact partial

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
ZcashFoundation zebra unaffected
Version Status Constraints
0 affected < 4.5.0
4.5.0 unaffected —
ZcashFoundation zebra unaffected
Version Status Constraints
0 affected < 8.0.0
8.0.0 unaffected —

No data.

No data.

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Vendors Products
Zcashfoundation Subscribe
Zebra Subscribe
Zfnd Subscribe
Zebra Subscribe

Project Subscriptions

Vendors Products
Zcashfoundation Subscribe
Zebra Subscribe
Zfnd Subscribe
Zebra Subscribe
Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-443g-gwgp-49x4 cve-icon cve-icon
https://www.vulncheck.com/advisories/zebra-before-4.5.0-cpu-amplification-via-uncapped-getblocks-getheaders-locator-length cve-icon cve-icon
History

Fri, 02 Oct 2026 15:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Fri, 02 Oct 2026 13:15:00 +0000

Type Values Removed Values Added
First Time appeared Zcashfoundation
Zcashfoundation zebra
Vendors & Products Zcashfoundation
Zcashfoundation zebra

Fri, 02 Oct 2026 11:45:00 +0000

Type Values Removed Values Added
Description Zebra before 4.5.0 contains an uncontrolled resource consumption vulnerability that allows remote P2P peers to exhaust blocking-pool threads by sending oversized block locator vectors. Attackers can send getblocks or getheaders messages with up to 65,535 locator hashes, triggering per-hash chain lookups that degrade block validation, RPC, and mempool performance.
Title Zebra before 4.5.0 CPU Amplification via Uncapped getblocks/getheaders Locator Length
First Time appeared Zfnd
Zfnd zebra
Weaknesses CWE-770
CPEs cpe:2.3:a:zfnd:zebra:*:*:*:*:*:*:*:*
Vendors & Products Zfnd
Zfnd zebra
References
Metrics cvssV3_1

{'score': 3.7, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L'}

cvssV4_0

{'score': 6.3, 'vector': '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'}

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-10-02T14:51:28.130Z

Reserved: 2026-10-02T00:50:26.604Z

Link: CVE-2026-104436

cve-icon Vulnrichment

Updated: 2026-10-02T14:51:25.345Z

cve-icon NVD

Status : Deferred

Published: 2026-10-02T12:17:14.210

Modified: 2026-10-02T17:59:09.430

Link: CVE-2026-104436

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-10-02T13:00:13Z

Weaknesses