CVE-2026-27645
MediumPublic exploitchangedetection.io Vulnerable to Reflected XSS in RSS Single Watch Error Response
Published Feb 25, 2026 · Updated Aug 12, 2026 · Also known as GHSA-mw8m-398g-h89w, PYSEC-2026-2125
Key Facts
Routine patching- CVE-2026-27645 is a medium-severity vulnerability (CVSS 6.1 v3.1) affecting Changedetection (Webtechnologies), changedetection-io (pypi), changedetection.io (pypi).
- It is not listed in any known-exploited vulnerabilities catalog. Public exploit code is available.
- EPSS estimates a 0.5% probability of exploitation in the next 30 days.
- Fixed versions are available, including changedetection-io 0.53.7, changedetection-io 0.54.1, changedetection.io 0.53.7.
- Brandefense priority: routine patching, as no exploitation is known and its severity is moderate or low.
CVSS v3.1
6.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
EPSS (30-day exploit likelihood)
0.5%
Higher than 41.5% of all scored CVEs
Exploited in the wild
No known
Not in a known-exploited catalog
Public exploit code
Available
Proof-of-concept or weaponized module
Get the full CVE-2026-27645 brief as a PDF
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Description
changedetection.io is a free open source web page change detection tool. In versions prior to 0.54.1, the RSS single-watch endpoint reflects the UUID path parameter directly in the HTTP response body without HTML escaping. Since Flask returns text/html by default for plain string responses, the browser parses and executes injected JavaScript. Version 0.54.1 contains a fix for the issue.
Affected Products
4 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| ChangedetectionWebtechnologies | See advisory | 0.54.1 |
| changedetection-iopypi | See advisory | 0.53.7 |
| changedetection.iopypi | >= < 0.54.1 | 0.53.7 |
Patched Releases
changedetection-io
0.53.7, 0.54.1
changedetection.io
0.53.7
Changedetection
0.54.1
Timeline
Publicly disclosed
Feb 25, 2026
Last updated
Aug 12, 2026
Weakness Type
- CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
References
- advisoryGHSA advisory
- advisoryhttps://github.com/CVEProject/cvelistV5/tree/main/cves/2026/27xxx/CVE-2026-27645.json
- advisoryhttps://nvd.nist.gov/vuln/detail/CVE-2026-27645
- articlehttps://github.com/dgtlmoon/changedetection.io/commit/a385c89abf44b52fcfa20c7c6a6dd3047c4c1eb5
- articlehttps://github.com/dgtlmoon/changedetection.io/security/advisories/GHSA-mw8m-398g-h89w
FAQ
Common Questions.
changedetection.io is a free open source web page change detection tool.
Affected: Changedetection (Webtechnologies); changedetection-io (pypi); changedetection.io (pypi) versions >= < 0.54.1. The full list is in the CVE brief.
It is not listed in any known-exploited vulnerabilities catalog.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
Public exploit code is available.
Fixed versions are available, including changedetection-io 0.53.7, changedetection-io 0.54.1, changedetection.io 0.53.7.
Brandefense priority: routine patching, as no exploitation is known and its severity is moderate or low.
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