# GO-2026-5841 - OOB read in github.com/klauspost/compress/s2

Source: https://junglewise.ai/threats/go-2026-5841-oob-read-in-github-com-klauspost-compress-s2-bc43eef4  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-07-27  
License: CC BY 4.0 with a link back

Severity: info · Published 2026-07-27

OOB read in github.com/klauspost/compress/s2

Technologies: [github.com/klauspost/compress (Go)](https://junglewise.ai/threats/technologies/github-com-klauspost-compress). Vendors: [Go](https://junglewise.ai/threats/vendors/go).

## 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 27 July 2026.

**Which products and versions are affected?** github.com/klauspost/compress (Go) SEMVER:introduced=1.16.0,fixed=1.18.7.

**Is there a fix for This vulnerability?** Yes. github.com/klauspost/compress (Go): upgrade to 1.18.7 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**Am I affected?** Check whether you run github.com/klauspost/compress (Go) 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

- github.com/klauspost/compress (Go): upgrade to 1.18.7 or later

  ```sh
  go get github.com/klauspost/compress@v1.18.7
  ```


## Affected products

- github.com/klauspost/compress (Go) SEMVER:introduced=1.16.0,fixed=1.18.7

## Related threats

- [Klaus Post compress zstd decoder panic on crafted input](https://junglewise.ai/threats/cve-2026-116591-compress-provides-various-compression-algorithms-prior-to-1-20-2)
- [klauspost compress signed integer overflow in s2.NewDict](https://junglewise.ai/threats/cve-2026-63209-compress-provides-various-compression-algorithms-prior-to-version)