Zstd safe: Out-of-bounds read
Affects zstd-safeSource GCVE Database
Rated by Threat Radar
- Patch
- Available – fixed in 8.2.0
Data as of 26 Oct 2026, 16:13 UTC
What to do
Upgrade zstd-safe to 8.2.0.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
crates.iozstd-safepkg:cargo/zstd-safeOther threats | Affected
| Fixed in
|
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Description
`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.