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Tracking
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| Source | ID | Title |
|---|---|---|
Github GHSA |
GHSA-4c8j-mgm4-qqvp | Remark42: Cross-Site Scripting (XSS) on /api/v1/img via content-type spoofing |
Sun, 21 Jun 2026 09:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Umputun
Umputun remark42 |
|
| Vendors & Products |
Umputun
Umputun remark42 |
Thu, 18 Jun 2026 04:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
ssvc
|
Tue, 16 Jun 2026 23:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| 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. | |
| Title | Remark42: Cross-Site Scripting (XSS) on /api/v1/img via content-type spoofing | |
| Weaknesses | CWE-436 CWE-79 |
|
| References |
| |
| Metrics |
cvssV3_0
|
Status: PUBLISHED
Assigner: GitHub_M
Published:
Updated: 2026-06-17T13:20:11.543Z
Reserved: 2026-05-22T20:18:20.365Z
Link: CVE-2026-48788
Updated: 2026-06-17T13:19:23.500Z
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OpenCVE Enrichment
Updated: 2026-06-20T23:05:14Z
Github GHSA