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.
CVE-2026-27645
MEDIUMPre-NVD 6.16.1Trending — 3 sources updated this weekElevated
EchelonGraph scoreLOW confidence
This medium-severity CVE scores 6.1 under the CNA's CVSS (NVD's own analysis pending). EPSS exploit-prediction score not yet available (the EPSS model rescores nightly; freshly-published CVEs typically appear within 48 hours). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
Triggered by: NVD CVSS baseline
Sources: cna:github_m
6.1EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
- Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 6.1Exploit: Elevated riskExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 6.1
- EG Score
- 6.1(low)
- EG Risk
- 43(Track)EG Risk 43/100SSVC: Track
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity61% × 45%Exploitation40% × 40%Automatability0% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- 0%
- EPSS %ILE
- 37%
- KEV
- Not listed
Published
February 25, 2026
Last Modified
June 17, 2026
References (3)
- security-advisories@githubhttps://github.com/dgtlmoon/changedetection.io/commit/a385c89abf44b52fcfa20c7c6a6dd3047c4c1eb5
- security-advisories@githubhttps://github.com/dgtlmoon/changedetection.io/security/advisories/GHSA-mw8m-398g-h89w
- 134c704f-9b21-4f2e-91b3-4a467353bcc0https://github.com/dgtlmoon/changedetection.io/security/advisories/GHSA-mw8m-398g-h89w
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 6× in last 7d / 6× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-08-01 04:16 UTCEPSS rescore
- 2026-07-30 16:27 UTCEPSS rescore
- 2026-07-30 01:30 UTCEPSS rescore
- 2026-07-28 15:36 UTCEPSS rescore
- 2026-07-27 12:55 UTCEG score recompute
- 2026-07-27 12:50 UTCOSV refresh
Publicly available exploits
(1 reference)Working exploit code is in the public domain. Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.
- Nucleihttp/cves/2026/CVE-2026-27645.yamlFirst seen Jan 1, 2026
Changedetection.io RSS Single Watch - Cross-Site Scripting
Open source ↗
Related CVEs(same CWE)
Frequently asked(5)
What is CVE-2026-27645?
CVE-2026-27645 is a medium vulnerability published on February 25, 2026. 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…
When was CVE-2026-27645 disclosed?
CVE-2026-27645 was first published in the National Vulnerability Database on February 25, 2026, with the most recent update on June 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-27645 actively exploited?
CVE-2026-27645 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 63.4% of all scored CVEs.
What is the CVSS score of CVE-2026-27645?
CVE-2026-27645 has a CVSS v3 base score of 6.1 (NVD). The EG score is currently aggregating — additional source signals are being incorporated as they become available..
How do I remediate CVE-2026-27645?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-27645, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-27645
Is Your Infrastructure Affected by CVE-2026-27645?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.