changedetection.io has an Arbitrary Local File Read via a crafted backup restore

Exploitation

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

CVSS

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

EPSS

• CVE-2026-43891: 0.35% estimated exploitation activity in the next 30 days; percentile 29.17 (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.

Details The vulnerability is caused by trusting attacker-controlled snapshot paths restored from backup files. The vulnerable flow starts in the backup restore logic. When a backup ZIP is restored, the application extracts the archive and copies each restored watch UUID directory directly into the live datastore using shutil.copytree(entry.path, dstdir). This preserves attacker-controlled files inside the restored watch directory, including history.txt. Relevant code: - changedetectionio/blueprint/backups/restore.py - changedetectionio/blueprint/backups/restore.py After restore, the application parses history.txt in the watch history property. This is the core trust-boundary issue. Relevant code: - changedetectionio/model/Watch.py - changedetectionio/model/Watch.py - changedetectionio/model/Watch.py The relevant logic is effectively: This has the following security consequence: - If the history.txt value is only a filename, it is resolved safely under self.datadir. - If the value…

Published by the source

5 May 2026, 21:16 UTC

Last modified by the source

8 Jul 2026, 08:14 UTC

Source last checked

26 Oct 2026, 13:42 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-8757-69j2-hx56

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-8757-69j2-hx56

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

# Patch Next advisory brief: CVE-2026-43891

Advisory: changedetection.io has an Arbitrary Local File Read via a crafted backup restore
IDs: CVE-2026-43891, GHSA-8757-69j2-hx56
Record: https://patchnext.com/advisories/cve-2026-43891 (revision 2, source checked 26 Oct 2026, 13:42 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: changedetection-io 0.55.1. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI changedetection-io: affected <= 0.54.10; fixed in 0.55.1

## 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-8757-69j2-hx56 (OSV record GHSA-8757-69j2-hx56 lists affected ranges: PyPI changedetection-io >=0 <0.55.1 (fixed))
- Verified: https://github.com/advisories/GHSA-8757-69j2-hx56 (GitHub-reviewed advisory GHSA-8757-69j2-hx56 lists affected ranges: PyPI changedetection-io >=0 <=0.54.10)

Commands are suggestions: review each one before running it.