Vulnerability in Zcashfoundation Zebra
CVE-2026-123557
ZcashFoundation Zebra zebrad before 7.0.0 contains a reachable assertion race condition that allows unauthenticated remote peers to abort the node by triggering disconnection during a blocked outbound send. Malicious peers can return empty FindBlocks or FindHeaders replies and stop reading their socket, dropping an unresolved MustUseClientResponseSender and terminating syncing nodes.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.9 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H.
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
Weakness classification (CWE)
References
- github.com/ZcashFoundation/zebra/security/advisories/GHSA-6v36-c42v-v98p (vendor-advisory)
- www.vulncheck.com/advisories/zebra-zebrad-before-7.0.0-reachable-assertion-dos-… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-123557?
- CVE-2026-123557 is a medium-severity vulnerability in Zcashfoundation Zebra, classified under Reachable Assertion. CVSS score: 5.9/10. Published 2026-11-08.
- How severe is CVE-2026-123557?
- Medium severity. CVSS v3 base score is 5.9 out of 10.