https://patchthecve.com/CVEs with upgrade or downgrade fix stepshttps://patchthecve.com/cve/CVE-2021-42766.htmlhttps://patchthecve.com/cve/CVE-2021-42766.htmlWed, 17 Jun 2026 04:10:06 +0000CRITICAL 9.1: The Proof-of-Stake (PoS) Ethereum consensus protocol through 2021-10-19 allows an adversary to cause a denial of service (long-range consensus chain reorganizations), even when this adversary has little stake and cannot influence network message propagation. This can cause a protocol stall, or an inhttps://patchthecve.com/cve/CVE-2021-42765.htmlhttps://patchthecve.com/cve/CVE-2021-42765.htmlWed, 17 Jun 2026 04:10:06 +0000HIGH 7.5: The Proof-of-Stake (PoS) Ethereum consensus protocol through 2021-10-19 allows an adversary to leverage network delay to cause a denial of service (indefinite stalling of consensus decisions).https://patchthecve.com/cve/CVE-2021-42764.htmlhttps://patchthecve.com/cve/CVE-2021-42764.htmlWed, 17 Jun 2026 04:10:06 +0000CRITICAL 9.1: The Proof-of-Stake (PoS) Ethereum consensus protocol through 2021-10-19 allows an adversary to cause a denial of service (delayed consensus decisions), and also increase the profits of individual validators, via short-range reorganizations of the underlying consensus chain.