# CVE-2023-42821: GO-2023-2074 - Parser out-of-bounds read caused by a malformed markdown input in github.com/gomarkdown/markdown

Source: https://junglewise.ai/threats/cve-2023-42821-markdown-vulnerable-to-out-of-bounds-read-while-parsing-citations  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2023-09-22  
License: CC BY 4.0 with a link back

CVE-2023-42821 · Severity: low · CVSS 3.1 · Published 2023-09-22

Parser out-of-bounds read caused by a malformed markdown input in github.com/gomarkdown/markdown

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

## Quick answers

**Is CVE-2023-42821 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2023-42821 being exploited in the wild.

**How severe is CVE-2023-42821?** Low severity, with a CVSS score of 3.1, published 22 September 2023.

**Which products and versions are affected?** github.com/gomarkdown/markdown (Go) SEMVER:introduced=0,fixed=0.0.0-20230922105210-14b16010c2ee.

**Is there a fix for CVE-2023-42821?** Yes. github.com/gomarkdown/markdown (Go): upgrade to 0.0.0-20230922105210-14b16010c2ee or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**Am I affected by CVE-2023-42821?** Check whether you run github.com/gomarkdown/markdown (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/gomarkdown/markdown (Go): upgrade to 0.0.0-20230922105210-14b16010c2ee or later

  ```sh
  go get github.com/gomarkdown/markdown@v0.0.0-20230922105210-14b16010c2ee
  ```


## Affected products

- github.com/gomarkdown/markdown (Go) SEMVER:introduced=0,fixed=0.0.0-20230922105210-14b16010c2ee

## Identifiers

- CVE-2023-42821
- GHSA-m9xq-6h2j-65r2
- GO-2023-2074

## Related threats

- [gomarkdown markdown IsSafeURL panic on short URLs](https://junglewise.ai/threats/cve-2026-102941-gomarkdown-markdown-issafeurl-panics-on-short-urls)
- [Go Markdown has an Out-of-bounds Read in SmartypantsRenderer](https://junglewise.ai/threats/cve-2026-40890-go-markdown-has-an-out-of-bounds-read-in-smartypantsrenderer)
- [GO-2024-3205 - Infinite loop in github.com/gomarkdown/markdown](https://junglewise.ai/threats/cve-2024-44337-infinite-loop-in-github-com-gomarkdown-markdown)