Core Rs Albatross CVE-2026-34061

CVSS 4.9 reflects a network-accessible vulnerability requiring high privileges (PR:H, validator proposer role) with no confidentiality or integrity impact but high availability impact (A:H). EPSS and KEV status are not provided in the input data, so real-world exploitation probability cannot be directly assessed. However, the risk signal analysis reveals critical operational risk despite moderate CVSS: exploitation requires compromised or malicious elected validator status (high barrier), but impact occurs post-consensus at finalization, potentially cascading to network halt if validators cannot propose valid blocks. Attack complexity is low (AC:L) given the straightforward validation bypass. The vulnerability's real-world priority is elevated beyond CVSS suggests because consensus networks depend on availability and this attack directly undermines finalization guarantees. For Nimiq network operators and validator operators, this is a critical patch despite lower CVSS; for general security consumers, risk is localized to Nimiq participants. The 1.3.0 patch's existence and specificity (exact commit 9d7d17c9163384e79f61cdbbfe9853ae57bb8bf7) confirms the issue was identified and resolved.

A malicious or compromised elected validator proposer constructs an election macro block with a header.interlink field that does not match the canonical next interlink state. The validator submits this block via the proposal path, where verify_macro_block_proposal() accepts it (no interlink check), allowing the validator to prevote and precommit the block hash. Tendermint reaches consensus on the block. When validators attempt to apply the finalized block via push, verify_block() detects InvalidInterlink and rejects it, potentially halting finalization for that round and degrading network liveness. Honest validators on 1.3.0+ reject the proposal before voting, preventing consensus failure.