changedetection.io is Vulnerable to SSRF via Watch URLs

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

8.6 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N

EPSS

• CVE-2026-27696: 0.50% estimated exploitation activity in the next 30 days; percentile 42.57 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary Changedetection.io is vulnerable to Server-Side Request Forgery (SSRF) because the URL validation function issafevalidurl() 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 such as: - http://169.254.169.254 - http://10.0.0.1/ - http://127.0.0.1/ 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. This is particularly severe because: - The fetched content is stored and viewable - this is not a blind SSRF - Watches are fetched periodically - creating a persistent SSRF that continuously accesses internal resources - By default, no password is set - the web UI is accessible without authentication - Self-hosted deployments typically run on cloud infrastructure where…

Published by the source

25 Feb 2026, 19:08 UTC

Last modified by the source

13 Jul 2026, 07:26 UTC

Source last checked

26 Oct 2026, 13:36 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-3c45-4pj5-ch7m

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-3c45-4pj5-ch7m

Preview the exact text before you copy it. Commands are read-only suggestions; review them before running anything.

# Patch Next advisory brief: CVE-2026-27696

Advisory: changedetection.io is Vulnerable to SSRF via Watch URLs
IDs: CVE-2026-27696, GHSA-3c45-4pj5-ch7m
Record: https://patchnext.com/advisories/cve-2026-27696 (revision 2, source checked 26 Oct 2026, 13:36 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.6)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: changedetection-io 0.54.1. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI changedetection-io: affected < 0.54.1; fixed in 0.54.1

## Suggested inspection (read-only)
- `python -m pip show changedetection-io`: prints the installed version. Run with the environment that serves production active.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on changedetection-io.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-3c45-4pj5-ch7m (OSV record GHSA-3c45-4pj5-ch7m lists affected ranges: PyPI changedetection-io >=0 <0.54.1 (fixed))
- Verified: https://github.com/advisories/GHSA-3c45-4pj5-ch7m (GitHub-reviewed advisory GHSA-3c45-4pj5-ch7m lists affected ranges: PyPI changedetection-io >=0 <0.54.1)

Commands are suggestions: review each one before running it.