CVE-2025-62780 is a low-severity (CVSS 3.5) Cross-site Scripting (XSS) vulnerability in changedetection-io. A fix is available for changedetection-io — see the affected versions and patch details below.
changedetection.io vulnerable to stored XSS in Watch update via API
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
Exploitation and automatability from CISA’s SSVC triage for CVE-2025-62780.
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.
How urgent is this, really
CVE-2025-62780 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,333 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
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
Summary
A Stored Cross Site Scripting is present in the changedetection.io Watch update API due to unsufficient security checks.
Details
Tested on changedetection.io version v0.50.24
REPOSITORY TAG IMAGE ID CREATED SIZE
ghcr.io/dgtlmoon/changedetection.io latest 0367276509a0 23 hours ago 599MB
When a user tries to add an unsafe URL as a Watch in the changedetection.io UI, the action is blocked with the error message "Watch protocol is not permitted by SAFE_PROTOCOL_REGEX or incorrect URL format".
This is catched by the function validate_url(test_url).
def validate_url(test_url):
# ...
from .model.Watch import is_safe_url
if not is_safe_url(test_url):
# This should be wtforms.validators.
raise ValidationError('Watch protocol is not permitted by SAFE_PROTOCOL_REGEX or incorrect URL format')
When instead the Watch API is used, this check is not performed resulting in unsafe URLs added as Watch.
PoC
Update an existing watch with an unsafe URL
curl -X PUT "http://example.site/api/v1/watch/1242e1c5-d59e-4352-0078-203a55b21282" \
-H "x-api-key: XXX" \
-H "Content-Type: application/json" \
-d '{
"url": "javascript:alert(document.domain)",
"title": "XSS PoC",
"paused": false
}'
Impact
Two scenarios are possibile:
- An attacker can insert a new watch with an arbitrary URL which really points to a web page. Once the HTML content is retrieved, the attacker updates the URL with a JavaScript payload.
- An attacker substitutes the URL in an existing watch with a new URL that is in reality a JavaScript payload.
When the user clicks on Preview and then on the malicious link, the JavaScript malicious code is executed.
<img width="1200" height="643" alt="poc1" src="https://github.com/user-attachments/assets/db81e0c7-b6d3-4332-b15d-a688a48c3227" /> <br> <img width="1200" height="643" alt="poc2" src="https://github.com/user-attachments/assets/e704b37c-d339-4322-9fc0-ad50dd86b31d" />Credits
Edoardo Ottavianelli @edoardottt
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | changedetection-io | all versions | 0.50.34pip install --upgrade 'changedetection-io==0.50.34' |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for changedetection-io, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update changedetection-io to 0.50.34 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-62780 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 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2025-62780 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2025-62780. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
How to detect CVE-2025-62780
A community-maintained Nuclei template exists for this CVE. You can scan for it directly:
nuclei -id cve-2025-62780 -u https://target- Template
- ChangeDetection.io <= v0.50.33 - Stored XSS via Watch API
- Severity
- medium
- Impact
- Attackers can execute arbitrary JavaScript in users' browsers, potentially stealing data or performing actions on behalf of the user.
- Remediation
- Update to version 0.50.34 or later.
Template by ProjectDiscovery nuclei-templates (0x_Akoko), MIT licensed. View the full template. Scan only systems you are authorised to test.
Frequently Asked Questions
Is CVE-2025-62780 in your dependencies?
O3 Security finds CVE-2025-62780 across PyPI dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.