Read the docs
TI-2026-86702 Aliases CVE-2026-123560GHSA-53c4-wq6g-vxqh

Incomplete cleanup in Zebra lets peers stall initial sync

Priority MEDIUM 53CWE-459Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
—
Confidentiality · integrity · availability
None · None · High
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA.

Summary

Zebra before 7.0.0 from the Zcash Foundation contains an incomplete cleanup flaw (CWE-459) that lets unauthenticated peers stall initial sync. A peer serves a forged checkpoint block body with bad authorizing data near the final checkpoint, which leaves rejected hashes in the sent-hash set. The node then stops requesting blocks until it restarts.

Written with Claude Haiku 5.5 from the sources below · 2026-11-08

Description from the CNA

Zebra before 7.0.0 contains an incomplete cleanup vulnerability that allows unauthenticated peers to stall initial sync by serving a forged checkpoint block body. Attackers can supply a body with forged authorizing data near the final checkpoint, leaving rejected hashes in the sent-hash set so the node stops requesting blocks until restart.

Why it matters now

Fix Fixed zebra (ZcashFoundation): 7.0.0

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
ZcashFoundationzebrabefore 7.0.07.0.0Patch availableCNA
  • zebra VendorZcashFoundation Affected before 7.0.0 Fixed in 7.0.0 Patch available CNA

Remediation

Upgrade zebra to version 7.0.0, which is the first fixed version.

Written with Claude Haiku 5.5 from the sources below · 2026-11-08

  • Fix · CNA zebra (ZcashFoundation) Fixed in 7.0.0

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Release ·

    ZcashFoundation zebra 7.0.0

    7 records Highest priority Priority MEDIUM 7 MEDIUM

    Other records, highest priority first

    • TI-2026-86701 Quadratic signature hashing in Zcash Zebra enables denial of servicePriority MEDIUM 53
    • TI-2026-86700 Improper cleanup stalls Zebra checkpoint sync via a malicious peerPriority MEDIUM 53
    • TI-2026-86697 Denial of service in Zebra via unscored script verification failuresPriority MEDIUM 53
    Show all 7 records →

Timeline

  1. 2026-11-08 Threatist record created from CVE-2026-123560
  2. 2026-11-08 Alias added: GHSA-53c4-wq6g-vxqh

References

Advisory 1

  • TI-2026-66079 Zebra before 4.4.0 Consensus Split via SIGHASH_SINGLE Missing-Output Handling CVSS 4.0HIGH 8.3
  • TI-2026-37850 ZEBRA: Mempool transaction admission denial via single-peer inbound queue saturation CVSS 3.1MEDIUM 5.3
  • TI-2026-71182 Improper block validation in Zebra gossip lets peers drop new blocks CVSS 4.0MEDIUM 6.3
  • TI-2026-29537 Zebra: addr/addrv2 Deserialization Resource Exhaustion CVSS 4.0MEDIUM 6.3
  • TI-2026-86701 Quadratic signature hashing in Zcash Zebra enables denial of service CVSS 4.0HIGH 8.7
  • TI-2026-86700 Improper cleanup stalls Zebra checkpoint sync via a malicious peer CVSS 4.0HIGH 8.7
See all 51 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences