{"id":"RUSTSEC-2026-0403","revision":null,"records":[{"revision":"3fac3702eb8344f3a56a12d87a6f519c","observedAt":"2026-10-26T14:35:44.727+00:00","statement":{"source":"osv","id":"RUSTSEC-2026-0403","aliases":[],"title":"Uninitialized memory exposed when streaming decompression of a legacy frame fails","description":"When decompression fails inside a legacy (zstd v0.4 to v0.7) frame, the\nbundled zstd library reports the output buffer as fully written although\nnothing was written. `DCtx::decompress_stream` committed that position even\non error, and for a `Vec<u8>` destination this extended the vector's length\nover uninitialized memory.\n\nLegacy support is enabled by default. A 5- or 6-byte corrupt legacy frame is\nenough: through `zstd::stream::write::Decoder`, up to 32 KiB of stale heap\nmemory is then passed to the wrapped writer on the next `write()` or\n`flush()`, or when an `auto_flush()`/`on_flush()` decoder is dropped. Whether\nthis reaches an attacker depends on where the application sends the\ndecompressed output. `zstd::stream::read::Decoder`, `zstd::decode_all` and\nthe bulk API are not affected.\n\nBefore zstd-safe 4.0.0, output buffers could only be initialized slices.\nThe zstd crate's own writer had the same flaw from 0.4.22 to 0.7.x, which is\ncovered by a separate advisory.\n\nThe flaw was corrected by only committing the buffer positions of a\nsuccessful call.","state":0,"publishedAt":"2026-10-16T12:00:00+00:00","modifiedAt":"2026-10-26T14:00:05.7874412+00:00","affected":[{"ecosystem":"crates.io","name":"zstd-safe","ranges":[{"type":"SEMVER","events":[{"kind":"introduced","version":"4.0.0"},{"kind":"fixed","version":"8.2.0"}]}],"versions":[],"rawVersionEvidence":null}],"metrics":[],"references":["https://crates.io/crates/zstd-safe","https://rustsec.org/advisories/RUSTSEC-2026-0403.html","https://github.com/gyscos/zstd-rs/commit/006e1d1ad1eeaf6b5d4c28329e70217adabcec43","https://github.com/gyscos/zstd-rs/pull/384"],"sourceUrl":"https://osv.dev/vulnerability/RUSTSEC-2026-0403","license":"OSV · upstream source license applies","key":"osv:RUSTSEC-2026-0403","identifiers":["RUSTSEC-2026-0403"]},"retained":false,"historicalAffected":[]}],"coverage":[{"source":"cisa-kev:global","scope":"Complete CISA KEV catalog; all vendors. Missing entries do not establish absence of exploitation.","generation":"2026-10-28T10:33:32.5344446+00:00","complete":true,"records":1760,"lastAttemptAt":"2026-10-28T10:33:32.5344446+00:00","lastSuccessAt":"2026-10-28T10:33:32.6834837+00:00","error":null,"lastVerifiedAt":"2026-10-28T10:33:32.6834858+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-d2186f400c54d65f61687f78bb1a00d184d2e215877d0194d7ed70caee809a44-dbe935b5c0445aa8bf0ad6eee2fdccbed1511848550405783cb6764f13f2cea1","complete":true,"records":415637,"lastAttemptAt":"2026-10-28T10:33:28.1218743+00:00","lastSuccessAt":"2026-10-28T10:33:28.0918568+00:00","error":null,"lastVerifiedAt":"2026-10-28T10:33:28.1218743+00:00","snapshotPublishedAt":"2026-10-28T10:28:43+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-90206abab09f43eb8aa51b6b52380ca8","complete":false,"records":13205,"lastAttemptAt":"2026-10-28T10:34:26.3885801+00:00","lastSuccessAt":"2026-10-28T10:34:26.4527863+00:00","error":null,"lastVerifiedAt":"2026-10-28T10:34:26.4527863+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":"2026-10-28T10:33:32.5344446+00:00","complete":true,"records":1093,"lastAttemptAt":"2026-10-28T10:33:32.5344446+00:00","lastSuccessAt":"2026-10-28T10:33:32.6846081+00:00","error":null,"lastVerifiedAt":"2026-10-28T10:33:32.6846084+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-8d16a738328646698f9217d8ea11893c","complete":true,"records":13449,"lastAttemptAt":"2026-10-28T10:33:33.1463542+00:00","lastSuccessAt":"2026-10-27T22:48:29.491+00:00","error":null,"lastVerifiedAt":"2026-10-27T22:48:29.491+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":13514,"expectedIdentifiers":13514,"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-f7cb12508d9e6a348c8a60f772ed85529cc80cd2ff853da1099b57754b20e943","complete":true,"records":9790,"lastAttemptAt":"2026-10-28T10:33:28.4933633+00:00","lastSuccessAt":"2026-10-27T21:49:03.9756799+00:00","error":null,"lastVerifiedAt":"2026-10-28T10:33:28.4933633+00:00","snapshotPublishedAt":"2026-10-27T21:48:11+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-72e5e79de0026dd0562d40734074a2236a06886643d67182b8381eaee757dbf7","complete":true,"records":1966,"lastAttemptAt":"2026-10-28T10:33:28.2877501+00:00","lastSuccessAt":"2026-10-27T21:46:38.0277323+00:00","error":null,"lastVerifiedAt":"2026-10-28T10:33:28.2877501+00:00","snapshotPublishedAt":"2026-10-27T21:18:15+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-9cc0e41ed4e75d0c111bed7fd0bbcd4f139c80cc1fc67f8c3d9a33a41da846ad","complete":true,"records":3002,"lastAttemptAt":"2026-10-28T10:33:32.5040876+00:00","lastSuccessAt":"2026-10-28T10:33:32.3653779+00:00","error":null,"lastVerifiedAt":"2026-10-28T10:33:32.5040876+00:00","snapshotPublishedAt":"2026-10-28T09:02:50+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-2ba4ef78ff3a54a3ff2eeaf8e09b7b84901727f582723b80c5b0279e777b2781","complete":true,"records":230857,"lastAttemptAt":"2026-10-28T10:33:28.3916004+00:00","lastSuccessAt":"2026-10-28T09:35:14.9469514+00:00","error":null,"lastVerifiedAt":"2026-10-28T10:33:28.3916004+00:00","snapshotPublishedAt":"2026-10-28T09:33:01+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null}]}