{"id":"EUVD-2026-37511","revision":"e33c17432f2d46d5bb6bf61161016e88","records":[{"revision":"e33c17432f2d46d5bb6bf61161016e88","observedAt":"2026-11-03T10:00:04.251+00:00","statement":{"source":"euvd","id":"EUVD-2026-37511","aliases":["CVE-2026-48788","GHSA-4c8j-mgm4-qqvp"],"title":"Remark42 is a self-hosted comment engine for blogs, articles, or any other place where readers can add comments. Versions 1.6.0 through 1.15.0 contain a Cross-Site Scripting (XSS) vulnerability exploitable through content-type spoofing. The…","description":"Remark42 is a self-hosted comment engine for blogs, articles, or any other place where readers can add comments. Versions 1.6.0 through 1.15.0 contain a Cross-Site Scripting (XSS) vulnerability exploitable through content-type spoofing. The Remark42 image proxy fetches an arbitrary remote URL and re-serves the response from Remark42's own origin. During the download phase, the proxy determines whether the resource is an image by inspecting only the Content-Type header advertised by the remote server, never examining the actual bytes; during the serving phase, it instead derives the response Content-Type by sniffing those bytes with http.DetectContentType. An attacker can exploit this inconsistency by hosting a URL that advertises Content-Type: image/png while returning an HTML/JavaScript body: the download check accepts it as an image, the serving path sniffs the body and emits Content-Type: text/html, and the browser renders the attacker-controlled HTML/JavaScript as a document within Remark42's origin. Exploitation requires no Remark42 account on the target instance; the attacker only needs to host the malicious upstream URL and deliver the proxy link to a victim by any means, such as email, direct message, or a link on another website. This issue has been fixed in version 1.16.0.","state":0,"publishedAt":null,"modifiedAt":null,"affected":[],"metrics":[{"system":"EUVD CVSS 3.0","vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:N","score":8.2,"severity":null}],"references":["https://github.com/umputun/remark42/security/advisories/GHSA-4c8j-mgm4-qqvp","https://github.com/umputun/remark42/commit/78d6de6bce1e961f023969da3ec8a00dd80c9ae8","https://github.com/umputun/remark42/releases/tag/v1.16.0"],"sourceUrl":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-37511","license":"ENISA EUVD · source terms and attribution apply","enrichment":{"sourceStatus":null,"weaknesses":[],"productCriteria":[],"sourceDates":{"datePublished":"Jun 16, 2026, 10:29:38 PM","dateUpdated":"Jun 17, 2026, 1:20:11 PM"},"relatedAdvisories":[],"note":"EUVD source date text has no stated timezone and is retained without inventing a UTC instant. Related bulletin membership is not an alias, common cause or applicability claim. A missing vector with a zero score is treated as unrated. Complete vendor/product and underlying source evidence remains in the original JSON."},"key":"euvd:EUVD-2026-37511","identifiers":["EUVD-2026-37511","CVE-2026-48788","GHSA-4c8j-mgm4-qqvp"]},"retained":false,"historicalAffected":[]}],"coverage":[]}