{"id":"RUSTSEC-2026-0348","summary":"Brotli certificate decompression can allocate up to 1 GiB before authentication","details":"The built-in Brotli certificate decompressor (enabled by the non-default\n`brotli` crate feature) bounded the size of the decompressed output, but\naccepted a peer-selected history window. Brotli's large-window extension was\nenabled, so a five-byte header could cause an allocation of 1 GiB. A peer can\nabort a process whose allocator cannot satisfy that request.\n\nNo trusted certificate is required by the attacker. Affected configurations are:\n\n- clients that enable the `brotli` feature and connect to a malicious server, and\n- servers that enable the `brotli` feature and request client certificates.\n\nApplications that do not enable the `brotli` feature are not affected.","aliases":["GHSA-h2v8-394m-p7vv"],"modified":"2026-10-14T13:30:02.480925286Z","published":"2026-10-14T12:00:00Z","database_specific":{"license":"CC0-1.0"},"references":[{"type":"PACKAGE","url":"https://crates.io/crates/rustls"},{"type":"ADVISORY","url":"https://rustsec.org/advisories/RUSTSEC-2026-0348.html"},{"type":"WEB","url":"https://github.com/rustls/rustls/pull/3297"}],"affected":[{"package":{"name":"rustls","ecosystem":"crates.io","purl":"pkg:cargo/rustls"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0.23.9"},{"fixed":"0.23.46"}]}],"ecosystem_specific":{"affected_functions":null,"affects":{"functions":[],"arch":[],"os":[]}},"database_specific":{"informational":null,"categories":["denial-of-service"],"cvss":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L","source":"https://github.com/rustsec/advisory-db/blob/osv/crates/RUSTSEC-2026-0348.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L"}]}