CVE-2026-29039
changedetection.io: XPath - Arbitrary File Read via unparsed-text()
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Blast Radius
changedetection-ioReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
changedetection.io is a free open source web page change detection tool. Prior to version 0.54.4, the changedetection.io application allows users to specify XPath expressions as content filters via the include_filters 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. This issue has been patched in version 0.54.4.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | changedetection-io | all versions | 0.54.4 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for changedetection-io. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update changedetection-io to 0.54.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-29039 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-29039 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-29039. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-29039 in your dependencies?
O3 detects CVE-2026-29039 across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.