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RUSTSEC-2026-0401 json

Out-of-bounds read in `train_from_buffer` when sample sizes overflow

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

`ZDICT_trainFromBuffer` is never told the length of the samples buffer, so `train_from_buffer` checked that the sample sizes add up to it. With overflow checks off, as in release builds, that sum wrapped around: sizes totalling 2^64 plus the buffer length passed the check, and the trainer read past the end of the buffer. `zstd::dict::from_continuous` relies on this check from zstd 0.4.10; older versions of zstd had their own, covered by a separate advisory.

This requires the sample sizes to come from an untrusted source. The flaw was corrected by summing the sizes with overflow checks.

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
>=0.0.0-0, <7.4.0
>=8.0.0-0, <8.2.0
7.4.0
8.2.0

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.