Is This vulnerability exploited in the wild?

No. Junglewise Threat Intelligence has no report of This vulnerability being exploited in the wild.

How severe is This vulnerability?

Informational severity, published 16 October 2026.

Which products and versions are affected?

zstd-safe (crates.io) SEMVER:introduced=7.2.2,fixed=8.2.0; Gyscos Zstd-Safe 7.2.2 to 8.1.x.

Is there a fix for This vulnerability?

Yes. zstd-safe (crates.io): upgrade to 8.2.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is This vulnerability attacked?

It is attacked over the network.

Check whether you run zstd-safe (crates.io) or Gyscos Zstd-Safe at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

zstd-safe Seekable null or out-of-bounds seek table read

Severity: info · Published 2026-10-16

The zstd-safe library, a Rust wrapper for the Zstandard compression C library, has a flaw in how it handles seek tables for decompression of multi-frame compressed data. An attacker can craft a malicious compressed file that causes the library to read from invalid memory locations, leading to memory corruption, information disclosure, or denial of service in applications that decompress untrusted data.

Technologies: zstd-safe (crates.io), Gyscos Zstd-Safe. Vendors: crates.io, Gyscos.

Quick answers

Is This vulnerability exploited in the wild?: No. Junglewise Threat Intelligence has no report of This vulnerability being exploited in the wild.
How severe is This vulnerability?: Informational severity, published 16 October 2026.
Which products and versions are affected?: zstd-safe (crates.io) SEMVER:introduced=7.2.2,fixed=8.2.0; Gyscos Zstd-Safe 7.2.2 to 8.1.x.
Is there a fix for This vulnerability?: Yes. zstd-safe (crates.io): upgrade to 8.2.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is This vulnerability attacked?: It is attacked over the network.
Am I affected?: Check whether you run zstd-safe (crates.io) or Gyscos Zstd-Safe at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

zstd-safe (crates.io): upgrade to 8.2.0 or later
```
cargo update -p zstd-safe
```

Technical details

The Seekable component failed to track initialization state, allowing uninitialized or failed initialization to proceed with decompression operations that read a NULL seek table from the C library. Additionally, the frame_decompressed_size function reads one entry past the end of the seek table. This results in out-of-bounds memory reads with attacker-controlled compressed input, enabling information leak or crash scenarios. The fix enforces initialization state validation and bounds checking on frame index access.

Affected products

gyscos zstd-safe 7.2.2 to 8.1.x

Timeline

2026-10-16: disclosed
2026-10-26: advisory
2026-10-26: patched

References

This page as Markdown. Free to reuse under CC BY 4.0 with a link back.