What is CVE-2026-104436?

CVE-2026-104436 is a low-severity vulnerability in Zcashfoundation Zebra, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 3.7/10. Published 2026-10-02.

How severe is CVE-2026-104436?

Low severity. CVSS v3 base score is 3.7 out of 10.

Resource exhaustion in Zcashfoundation Zebra

CVE-2026-104436

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.

Published 2026-10-02 · last modified 2026-10-02.

CVSS v3 metric

CVSS v3 base score 3.7 (Low). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Zcashfoundation Zebra

Weakness classification (CWE)

CWE-770 — Allocation of Resources Without Limits or Throttling

References

github.com/ZcashFoundation/zebra/security/advisories/GHSA-443g-gwgp-49x4 (vendor-advisory)
www.vulncheck.com/advisories/zebra-before-4.5.0-cpu-amplification-via-uncapped-… (third-party-advisory)

Frequently asked questions

What is CVE-2026-104436?: CVE-2026-104436 is a low-severity vulnerability in Zcashfoundation Zebra, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 3.7/10. Published 2026-10-02.
How severe is CVE-2026-104436?: Low severity. CVSS v3 base score is 3.7 out of 10.