CVE-2026-27645 | changedetection.io Vulnerable to Reflected XSS in RSS Single Watch Error Response

Exp

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.

Published: 2026-02-25 Last update: 2026-02-25 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-27645 is rated Exploit Available (51.5/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.45%). 1 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2026-27645

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2026-27645

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.71% 0.45% -0.27%
2 2026-05-04 0.62% 0.71% +0.10%
3 2026-04-27 — 0.62% —

Full EPSS history (11 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-27645

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.1 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
 2.8 2.7 [email protected]

Weakness enumeration for CVE-2026-27645

GitHub Security Advisory for CVE-2026-27645

GHSA-mw8m-398g-h89w · Severity: medium · Ecosystem: pip — changedetection.io Vulnerable to Reflected XSS in RSS Single Watch Error Response

Affected software / configurations for CVE-2026-27645

Vendor Product Version Raw CPE
webtechnologies changedetection < 0.54.1 cpe:2.3:a:webtechnologies:changedetection:*:*:*:*:*:*:*:*

References for CVE-2026-27645

cvelogic Threat Intelligence