vLLM tiktoken vocab file handler — local denial of service via TiktokenTokenizer::new

A denial-of-service flaw exists in vLLM's Rust-based tiktoken tokenizer vocab-file handling, crashing the affected component when triggered locally.

Low urgency given the local-attacker precondition, but worth tracking for any vLLM deployment that allows less-trusted local users (e.g., shared multi-user inference hosts) to interact with the tokenizer loading path.

A local attacker can trigger a flaw in the TiktokenTokenizer::new function of the tiktoken vocab file handler (rust/src/text/src/backend/hf/mod.rs), causing a crash and denial of service; exploitation requires local access, limiting the practical blast radius.

vllm-project vLLM, versions up to 0.29.0 (Rust tiktoken backend)

Track the upstream vLLM fix and upgrade when available; this is a local-only, low-severity issue and does not require emergency action for typical remote-facing deployments.