changedetection.io vulnerable to XPath - Arbitrary File Read via unparsed-text()

Exploitation

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

CVSS 4.0

8.8 · CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:P · score source

EPSS

• CVE-2026-29039: 0.54% estimated exploitation activity in the next 30 days; percentile 45.38 (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 - The changedetection.io application allows users to specify XPath expressions as content filters via the includefilters field. These XPath expressions are processed using the elementpath library which implements XPath 3.0/3.1 specification. - XPath 3.0 includes the unparsed-text() function which can read arbitrary files from the filesystem. The application does not validate or sanitize XPath expressions to block dangerous functions, allowing an attacker to read any file accessible to the application process. Data Flow Affected Code File: changedetectionio/htmltools.py Function: xpathfilter() Lines: 187-220 Validation (forms.py): Details - Navigate to the http://ewn9c0k01ghh7f588a7mij4y1w6iz8gb.tryneoai.com:5000/ instance - Create a new watch with any valid URL (e.g., https://example.com) - Edit the watch and set the "CSS/JSONPath/JQ/XPath Filters" field to: - Save and trigger a recheck - View the preview/snapshot - the file contents will be displayed <img width="2800"…

Published by the source

4 Mar 2026, 20:59 UTC

Last modified by the source

13 Jul 2026, 07:26 UTC

Source last checked

26 Oct 2026, 13:36 UTC

1. Revision 3 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-6fmw-82m7-jq6p

2. Revision 2 · amended · 25 Oct 2026

   Reviewed OSV alias/range/CVSS4 correction; package source scopes and original publication preserved. No customer finding resolved.

3. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-6fmw-82m7-jq6p

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# Patch Next advisory brief: CVE-2026-29039

Advisory: changedetection.io vulnerable to XPath - Arbitrary File Read via unparsed-text()
IDs: CVE-2026-29039, GHSA-6fmw-82m7-jq6p
Record: https://patchnext.com/advisories/cve-2026-29039 (revision 3, 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 8.8)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: changedetection-io 0.54.4. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI changedetection-io: affected <= 0.54.3; fixed in 0.54.4

## 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-6fmw-82m7-jq6p (OSV record GHSA-6fmw-82m7-jq6p lists affected ranges: PyPI changedetection-io >=0 <0.54.4 (fixed))
- Verified: https://github.com/advisories/GHSA-6fmw-82m7-jq6p (GitHub-reviewed advisory GHSA-6fmw-82m7-jq6p lists affected ranges: PyPI changedetection-io >=0 <=0.54.3)

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