RUSTSEC-2026-0258: h2 unbounded empty DATA frames

> h2 unbounded empty DATA frames

| Details | |
| ------------------- | ---------------------------------------------- |
| Package | `h2` |
| Version | `0.3.27` |
| URL | [https://github.com/hyperium/hyper/security/advisories/GHSA-q83h-524g-xf6h](https://github.com/hyperium/hyper/security/advisories/GHSA-q83h-524g-xf6h) |
| Date | 2026-08-17 |
| Patched versions | `>=0.4.16` |

The h2 crate, used internally by hyper, had a flaw that would accept and queue empty DATA frames without limit.
If streams were not actively drained, this could lead to unbounded memory usage, or a panic if the length overflows.

Low severity.

Patched in v0.4.16.

See [advisory page](https://rustsec.org/advisories/RUSTSEC-2026-0258.html) for additional details.

Start by locating the h2 0.3.27 dependency in the Rust dependency manifests and lockfile. Update it to the patched 0.4.16 or newer release, then run the repository's existing test suite and confirm dependency resolution succeeds without introducing compatibility failures.

Written by the indexing model from the issue text.