RUSTSEC-2026-0392
Uninitialized memory exposed by `write::Decoder` on a corrupt legacy frame
From 0.4.22 to 0.7.x, the writer behind zstd::stream::write::Decoder set
its output buffer's length to its full capacity before each decompression
call, then to the position the call reported, and only checked for an error
afterwards. When decompression fails inside a legacy (zstd v0.4 to v0.7)
frame, the bundled zstd library reports the output as fully written although
nothing was written, so stale heap memory, up to the buffer size (32 KiB by
default), was passed to the wrapped writer.
Legacy support is enabled by default, and a few bytes of corrupt legacy frame are enough. Whether this reaches an attacker depends on where the application sends the decompressed output.
From 0.8.0, the writer uses zstd-safe's buffers, and the same flaw there is covered by the zstd-safe advisory for it, fixed in zstd-safe 8.2.0.
What each source reports
OSV No score
Uninitialized memory exposed by `write::Decoder` on a corrupt legacy frame
From 0.4.22 to 0.7.x, the writer behind zstd::stream::write::Decoder set
its output buffer's length to its full capacity before each decompression
call, then to the position the call reported, and only checked for an error
afterwards. When decompression fails inside a legacy (zstd v0.4 to v0.7)
frame, the bundled zstd library reports the output as fully written although
nothing was written, so stale heap memory, up to the buffer size (32 KiB by
default), was passed to the wrapped writer.
Legacy support is enabled by default, and a few bytes of corrupt legacy frame are enough. Whether this reaches an attacker depends on where the application sends the decompressed output.
From 0.8.0, the writer uses zstd-safe's buffers, and the same flaw there is covered by the zstd-safe advisory for it, fixed in zstd-safe 8.2.0.
- Record
RUSTSEC-2026-0392- Updated
- 2026-11-02
Affected packages
| Package | Affected | Fixed |
|---|---|---|
zstdcrates.io |
0.4.22 up to 0.8.0 | 0.8.0 |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
RUSTSEC-2026-0392 is a vulnerability with no CVSS score yet in zstd, published October 16, 2026. No source lists public exploit code. Fixed in zstd 0.8.0.