{"id":"RUSTSEC-2026-0400","aliases":[],"status":"published","title":"Use-after-free of a dictionary after a one-shot call on a context with an open stream","description":"The one-shot `DCtx` and `CCtx` methods assumed the C library resets the\ncontext, but it leaves an open stream as it is. When a stream was left\nunfinished on a context, a one-shot call such as `decompress_using_dict`\ncould leave the context pointing at the dictionary borrowed for that call,\nand the next streaming call resumed the stream against it after it was\nfreed: decompressed output then contained freed heap memory. On the\ncompression side, the stream resumed against the one-shot call's buffers.\n\nThis requires an application to use one context for both streaming and\none-shot calls without a reset in between. The flaw was corrected by\nresetting the session after one-shot calls whenever a stream may be open.","facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"published":"2026-10-16T12:00:00Z","modified":"2026-11-02T09:30:03Z","fixes":[{"ecosystem":"crates.io","package":"zstd-safe","fixed_in":["7.4.0","8.2.0"],"sources":["osv"]}],"affected":[{"source":"osv","ecosystem":"crates.io","package":"zstd-safe","ranges":[{"type":"SEMVER","events":[{"introduced":"3.0.1"},{"fixed":"7.4.0"},{"introduced":"8.0.0-0"},{"fixed":"8.2.0"}]}]}],"references":[{"url":"https://crates.io/crates/zstd-safe","tags":["package"]},{"url":"https://rustsec.org/advisories/RUSTSEC-2026-0400.html","tags":["advisory"]},{"url":"https://github.com/gyscos/zstd-rs/commit/d34502a0ed07f80ab2aa4c65059578e0466f2467","tags":["web"]},{"url":"https://github.com/gyscos/zstd-rs/pull/384","tags":["web"]}],"sources":{"osv":[{"id":"RUSTSEC-2026-0400","title":"Use-after-free of a dictionary after a one-shot call on a context with an open stream","description":"The one-shot `DCtx` and `CCtx` methods assumed the C library resets the\ncontext, but it leaves an open stream as it is. When a stream was left\nunfinished on a context, a one-shot call such as `decompress_using_dict`\ncould leave the context pointing at the dictionary borrowed for that call,\nand the next streaming call resumed the stream against it after it was\nfreed: decompressed output then contained freed heap memory. On the\ncompression side, the stream resumed against the one-shot call's buffers.\n\nThis requires an application to use one context for both streaming and\none-shot calls without a reset in between. The flaw was corrected by\nresetting the session after one-shot calls whenever a stream may be open.","status":"published","published":"2026-10-16T12:00:00Z","modified":"2026-11-02T09:30:03.42834157Z","updated_at":"2026-11-02T15:53:40.430679Z"}]}}