Bitcoin Core Discloses Medium-Severity Vulnerability That Could Stall Block Processing; Fix Included in Versions 29.2 and 30.0

Odaily: Bitcoin Core's security advisory disclosed a medium-severity vulnerability, CVE-2025-62859, which was made public on November 10, 2026. The vulnerability exists in versions prior to 29.2 and 30.0. A malicious node can exploit witness data tampering in compact blocks to stall the victim's block processing under specific conditions. After reconstructing a compact block and before checking witness data, the affected node clears its download state; if the check fails, the node instead requests the full block from the same node and waits for a 10-minute timeout. If an attacker controls three of the victim's high-bandwidth peers, or if the victim is running in -blockonly mode, the attack can be repeated indefinitely. The fix has been included in versions 29.2 and 30.0.