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RUSTSEC-2026-0402 json

Heap buffer overflow in `CCtx::try_clone` on a multithreaded context

published 26d ago modified 10d ago

cvss
—
not scored
cisa kev
Not listed
not in CISA's catalog
epss
—
no score, EPSS covers CVEs only
public exploits
0
none known

Summary

`CCtx::try_clone` (`experimental` feature, deprecated) copies tables sized from the context's applied parameters. Starting a multithreaded frame (`zstdmt` feature) replaces those parameters with the workers' without resizing the context's own tables, so after an abandoned single-threaded frame, the copy wrote up to 512 KiB past a heap allocation, or read past one. This became reachable with the bundled zstd 1.5.6.

The flaw was corrected by refusing `try_clone` (and the unsafe `compress_block`) once `NbWorkers` was set on the context.

Patch / fix

  • crates.io zstd-safe 7.4.0, 8.2.0

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Affected packages

ecosystem package affected fixed in
crates.io zstd-safe
>=4.1.4, <7.4.0
>=8.0.0-0, <8.2.0
7.4.0
8.2.0

References

Sources

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