{"id":"CVE-2026-48788","revision":"b7090c7df89c46e2a199bc68e29b2ec6","records":[{"revision":"b7090c7df89c46e2a199bc68e29b2ec6","observedAt":"2026-10-27T13:11:53.172+00:00","statement":{"source":"nvd","id":"CVE-2026-48788","aliases":[],"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":"2026-06-17T13:20:43.49+00:00","modifiedAt":"2026-10-25T23:10:00.167+00:00","affected":[],"metrics":[{"system":"CVSS 3.0 · security-advisories@github.com · Secondary","vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:N","score":8.2,"severity":"HIGH"}],"references":["https://github.com/umputun/remark42/commit/78d6de6bce1e961f023969da3ec8a00dd80c9ae8","https://github.com/umputun/remark42/releases/tag/v1.16.0","https://github.com/umputun/remark42/security/advisories/GHSA-4c8j-mgm4-qqvp"],"sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-48788","license":"NIST NVD usage terms; underlying source attribution retained","enrichment":{"sourceStatus":"Deferred","weaknesses":["CWE-79","CWE-436"],"productCriteria":[],"sourceDates":{"published":"2026-06-17T13:20:43.490","lastModified":"2026-10-25T23:10:00.167"},"relatedAdvisories":[],"note":"NVD analysis and CPE criteria are source context, not proof that a package or your environment is affected. Complete affected data, logical configurations and SSVC are retained in the original JSON."},"key":"nvd:CVE-2026-48788","identifiers":["CVE-2026-48788"]},"retained":false,"historicalAffected":[]}],"coverage":[]}