{"id":"RUSTSEC-2026-0348","revision":null,"records":[{"revision":"ee8e40a10944493280ec12309b5e229a","observedAt":"2026-10-27T16:45:46.193+00:00","statement":{"source":"osv","id":"GHSA-h2v8-394m-p7vv","aliases":["RUSTSEC-2026-0348"],"title":"Rustls: Brotli certificate decompression can allocate an attacker-controlled amount of memory up to 1 GiB before authentication.","description":"### Summary\n\nThe built-in (but disabled by default) Brotli certificate decoder bounds the output buffer but accepts an input-selected history window. A header of five bytes can specify a 1 GiB window allocation. A peer can abort a process whose allocator cannot satisfy that request. A client must enable Brotli and connect to the peer; a server must enable Brotli and request a client certificate. Neither direction requires a trusted attacker certificate.\n\n### Details\n\nrustls calls `BrotliDecompress` which enables Brotli's large-window extension. rustls applies a limit to certificates, but this applies to the decompressed result, and not to any internal allocations the process requires.\n\n### Impact\n\nClient applications that enable the `brotli` feature will be vulnerable to malicious servers. Server applications that enable the `brotli` feature and enable client authentication will be vulnerable to malicious clients.\n\nPotential for denial of service due to memory exhaustion from peers sending malicious Brotli-encoded certificates, for applications that enable Brotli decompression.\n\n### Acknowledgement\nThanks to OpenAI [OutboundDisclosures@openai.com](mailto:OutboundDisclosures@openai.com) for the disclosure.","state":0,"publishedAt":"2026-10-27T16:08:36+00:00","modifiedAt":"2026-10-27T16:15:05.3378195+00:00","affected":[{"ecosystem":"crates.io","name":"rustls","ranges":[{"type":"SEMVER","events":[{"kind":"introduced","version":"0"},{"kind":"fixed","version":"0.23.46"}]}],"versions":[],"rawVersionEvidence":null},{"ecosystem":"crates.io","name":"rustls","ranges":[{"type":"SEMVER","events":[{"kind":"introduced","version":"0.24.0-dev.1"},{"kind":"fixed","version":"0.24.0-dev.2"}]}],"versions":[],"rawVersionEvidence":null}],"metrics":[{"system":"CVSS_V3","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L","score":null,"severity":null},{"system":"Publisher rating","vector":null,"score":null,"severity":"LOW"}],"references":["https://github.com/rustls/rustls/security/advisories/GHSA-h2v8-394m-p7vv","https://github.com/rustls/rustls/pull/3297","https://github.com/rustls/rustls/pull/3354","https://github.com/rustls/rustls/commit/1aa987af37d0d79b98781d345895ac0059ce345c","https://github.com/rustls/rustls/commit/402b7b78b7ae87d59e19cf07ee07f3fc19e6537e","https://github.com/rustls/rustls","https://github.com/rustls/rustls/releases/tag/v/0.23.46","https://rustsec.org/advisories/RUSTSEC-2026-0348.html"],"sourceUrl":"https://github.com/advisories/GHSA-h2v8-394m-p7vv","license":"GitHub Advisory Database · CC-BY-4.0","key":"osv:GHSA-h2v8-394m-p7vv","identifiers":["GHSA-h2v8-394m-p7vv","RUSTSEC-2026-0348"]},"retained":false,"historicalAffected":[]},{"revision":"80920544afe848e4acd8e7c92f704d18","observedAt":"2026-10-24T13:19:54.901+00:00","statement":{"source":"osv","id":"RUSTSEC-2026-0348","aliases":["GHSA-h2v8-394m-p7vv"],"title":"Brotli certificate decompression can allocate up to 1 GiB before authentication","description":"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.","state":0,"publishedAt":"2026-10-14T12:00:00+00:00","modifiedAt":"2026-10-14T13:30:02.4809253+00:00","affected":[{"ecosystem":"crates.io","name":"rustls","ranges":[{"type":"SEMVER","events":[{"kind":"introduced","version":"0.23.9"},{"kind":"fixed","version":"0.23.46"}]}],"versions":[],"rawVersionEvidence":null}],"metrics":[{"system":"CVSS_V3","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L","score":null,"severity":null}],"references":["https://crates.io/crates/rustls","https://rustsec.org/advisories/RUSTSEC-2026-0348.html","https://github.com/rustls/rustls/pull/3297"],"sourceUrl":"https://osv.dev/vulnerability/RUSTSEC-2026-0348","license":"OSV · upstream source license applies","key":"osv:RUSTSEC-2026-0348","identifiers":["RUSTSEC-2026-0348","GHSA-h2v8-394m-p7vv"]},"retained":false,"historicalAffected":[]}],"coverage":[{"source":"cisa-kev:global","scope":"Complete CISA KEV catalog; all vendors. Missing entries do not establish absence of exploitation.","generation":"2026-10-30T16:47:08.0799506+00:00","complete":true,"records":1764,"lastAttemptAt":"2026-10-30T16:47:08.0799506+00:00","lastSuccessAt":"2026-10-30T16:47:08.2603913+00:00","error":null,"lastVerifiedAt":"2026-10-30T16:47:08.2603923+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"cve-program","scope":"Official CVE Program baseline and cumulative hourly delta; all vendors, published and rejected records","generation":"cve-7e2c4e7288f2c464ad8c61f3bb6017374714faedcc781283ac06a706ee1a820b-d7b222ecfb3b37ed75e1512e40fdcf28594abff2a8568f1274ffe87891d61caa","complete":true,"records":417228,"lastAttemptAt":"2026-10-30T16:45:32.5536592+00:00","lastSuccessAt":"2026-10-30T16:45:32.4100997+00:00","error":null,"lastVerifiedAt":"2026-10-30T16:45:32.5536592+00:00","snapshotPublishedAt":"2026-10-30T16:25:31+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"euvd","scope":"Rolling EUVD lookups of CVE aliases in current public OSV archives; 500 identifiers per refresh, rechecked after 48 hours. Not a global EUVD catalog. Successful not-found lookups count as checked; they do not imply withdrawal or safety. No reader inventory is sent.","generation":"enrichment-85f2e6ed06fd47b396d39d8d5a3d43ae","complete":false,"records":13527,"lastAttemptAt":"2026-10-30T16:52:07.90893+00:00","lastSuccessAt":"2026-10-30T16:52:07.9705389+00:00","error":null,"lastVerifiedAt":"2026-10-30T16:52:07.9705389+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"first-epss:nuget","scope":"FIRST EPSS for explicit CVE aliases in the collected public NuGet archive. Not a global EPSS backfill.","generation":"2026-10-30T16:47:08.0799506+00:00","complete":true,"records":1094,"lastAttemptAt":"2026-10-30T16:47:08.0799506+00:00","lastSuccessAt":"2026-10-30T16:47:08.2616584+00:00","error":null,"lastVerifiedAt":"2026-10-30T16:47:08.2616589+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"nvd","scope":"Rolling NVD lookups of CVE aliases in current public OSV archives; 500 identifiers per refresh, rechecked after 48 hours. Not a global NVD catalog. Successful not-found lookups count as checked; they do not imply withdrawal or safety. No reader inventory is sent.","generation":"enrichment-0f2f428ccf42491d9927e55626b8fc62","complete":false,"records":13545,"lastAttemptAt":"2026-10-30T16:47:33.5927086+00:00","lastSuccessAt":"2026-10-30T16:47:33.589+00:00","error":null,"lastVerifiedAt":"2026-10-30T16:47:33.589+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":13603,"expectedIdentifiers":13605,"failedIdentifiers":0},{"source":"osv:Go","scope":"Complete OSV Go ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"go-e091d9104aae1991994c868b5fad0248c9b288abafb7672fca8ae6500f97e080","complete":true,"records":9808,"lastAttemptAt":"2026-10-30T16:47:08.0351821+00:00","lastSuccessAt":"2026-10-30T15:47:48.5635219+00:00","error":null,"lastVerifiedAt":"2026-10-30T16:47:08.0351821+00:00","snapshotPublishedAt":"2026-10-30T15:23:39+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"osv:NuGet","scope":"Complete OSV NuGet ecosystem archive, including GitHub Advisory Database records; NuGet version matching only","generation":"nuget-2de9ccc5290f060c7aa63f89c25dd76f655a64ba1aba7c05c97fa3bee4f09899","complete":true,"records":1967,"lastAttemptAt":"2026-10-30T16:45:32.7049631+00:00","lastSuccessAt":"2026-10-28T20:55:34.2982937+00:00","error":null,"lastVerifiedAt":"2026-10-30T16:45:32.7049631+00:00","snapshotPublishedAt":"2026-10-28T20:03:08+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"osv:crates.io","scope":"Complete OSV crates.io ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"crates.io-f63fa91e750071ae88c9f82019ecd6c982fa4fcc1d3dc5ceb5d9c642fb6bf05c","complete":true,"records":3023,"lastAttemptAt":"2026-10-30T16:47:08.0492653+00:00","lastSuccessAt":"2026-10-30T11:49:36.4759887+00:00","error":null,"lastVerifiedAt":"2026-10-30T16:47:08.0492653+00:00","snapshotPublishedAt":"2026-10-30T11:18:14+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"osv:npm","scope":"Complete OSV npm ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"npm-5a294989873fb9168d8ae38882a7a1451dd62315f67b71899ceec86dfb29d13b","complete":true,"records":230954,"lastAttemptAt":"2026-10-30T16:47:07.9043788+00:00","lastSuccessAt":"2026-10-30T16:47:06.5719002+00:00","error":null,"lastVerifiedAt":"2026-10-30T16:47:07.9043788+00:00","snapshotPublishedAt":"2026-10-30T16:33:30+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null}]}