Bitcoin Core discloses three patched security vulnerabilities, including a high-severity issue that could prevent miners from generating block templates

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BlockBeats News, November 11, Bitcoin Core publicly disclosed three previously patched security vulnerabilities, one of which was rated high severity. The vulnerability, designated CVE-2025-62861, affects versions 28.0 through 28.2 and 29.0 through 29.1. During chain reorganizations, the "sibling eviction" rule for version 3 transactions was still incorrectly enforced, potentially evicting a transaction from the mempool while leaving its descendants behind, resulting in an inconsistent mempool state. Affected miner nodes would be unable to generate valid block templates and would need to restart their nodes to resume block production. The issue was discovered and responsibly disclosed by Niklas Goegge in September 2025.

The other two vulnerabilities were rated medium severity. CVE-2025-62859, reported by Eugene Siegel, allowed a malicious node to exploit SegWit malleability in compact blocks to delay the peer's block processing by up to approximately 10 minutes. This disruption could be repeated if the attacker controlled all three of the peer's high-bandwidth peers, or if the peer was running in -blocksonly mode. CVE-2025-62860 affected nodes with the non-default -whitelist setting enabled where the whitelisted network range covered the Tor proxy address; incoming Tor connections could be incorrectly granted whitelist permissions, thereby relaxing certain denial-of-service restrictions and privacy protections. Bitcoin Core stated that at the time, thousands of reachable mainnet nodes had consequently opened their whitelists to incoming Tor connections; nodes without this setting enabled were unaffected. Fixes for these vulnerabilities were released with 30.0 on October 10, 2025, 29.2 on October 14, and the subsequently released 28.3, respectively. The last affected version reached end of maintenance on October 27 of this year.

Original link: https://m.theblockbeats.info/flash/376804

Key points

Bitcoin Core publicly disclosed three previously fixed security vulnerabilities, one of which was rated high severity, while the other two were rated medium severity.
CVE-2025-62861 affects versions 28.0 through 28.2 and 29.0 through 29.1; during chain reorganization, the "sibling eviction" rule for version 3 transactions may be incorrectly enforced, leading to mempool state inconsistency, causing affected mining nodes to be unable to generate valid block templates, requiring a node restart to resume block production.
CVE-2025-62861 was discovered by Niklas Goegge in September 2025 and responsibly disclosed.
CVE-2025-62859 was reported by Eugene Siegel; a malicious node can exploit segwit malleability in compact blocks to delay the counterparty's processing of a block by up to approximately 10 minutes. If the attacker controls all three of the counterparty's high-bandwidth peers, or if the counterparty is running in -blocksonly mode, this disruption can be carried out repeatedly.
CVE-2025-62860 affects nodes that have enabled the non-default -whitelist setting and whose whitelisted network ranges cover the Tor proxy address; incoming Tor connections may be incorrectly granted whitelist privileges, thereby relaxing some denial-of-service restrictions and privacy protections.
Bitcoin Core stated that thousands of accessible mainnet nodes consequently opened their whitelists to incoming Tor connections; nodes that had not enabled this setting were unaffected.
Reports say the fixes were released with version 30.0 on October 10, 2025, version 29.2 on October 14, and subsequently released version 28.3; the last affected version reached end of life on October 27.

AI-assisted interpretation

The following is analysis, separate from reported facts. Verify important claims independently.

The report introduced three already-fixed Bitcoin Core vulnerabilities: one that could prevent some miners from generating block templates, one that could delay block processing, and another that could cause nodes with specific configurations to relax restrictions on incoming Tor connections.

Why it matters to readers

The impact of the vulnerability depends on the node version and configuration. Reports mention that a fixed version has been released, but do not specify how many nodes are still running affected versions, nor do they report any current network or market impact.

If you run a Bitcoin Core node, you can compare it against the affected versions and configurations in the report and pay attention to upgrade status; simply holding BTC is not the same thing as running a node.

Risks and unknowns

The year "this year" mentioned in the report corresponds to which 1 year is not specified in the original text, so it is impossible to determine the year when the last affected version stopped being maintained.
No information was provided on the number of nodes still running the currently affected version, the actual impact on block production, or the proportion of subsequent upgrades.

Bitcoin Core discloses three patched security vulnerabilities, including a high-severity issue that could prevent miners from generating block templates

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