Researchers presented a Solana Proof-of-History (PoH) timing attack at USENIX Security on Aug. 12 after privately disclosing it to Solana developers in December 2025. The protocol-valid technique lets a scheduled leader repeatedly re-anchor PoH, slowing logical time while physical time advances and extending its transaction-selection window. In a fork-assisted version using TowerBFT, the legacy fork-choice mechanism, an attacker with less than 33% of stake could isolate or suppress an honest leader's block under the modeled conditions. Anza's 50,000 SOL Alpenglow competition closed on Aug. 19 at 16:00 UTC, but its rules excluded behavior reachable only while Alpenglow was inactive, apparently placing the paper's legacy path outside the contest's review. Alpenglow is intended to replace PoH and TowerBFT with Votor and remove the attack's prerequisites. Alpenglow code was included in Agave 4.2 for community test clusters but was not activated on mainnet and was expected to launch with Agave 4.3. Anza and the Solana Foundation have not published a paper-specific implementation analysis. Tests and simulations established a protocol-valid fairness and latency issue, while public-mainnet measurements were suggestive but did not establish a live exploit, theft, demonstrated manipulation, or a consensus-safety break.