Detections
Analytics

SCA: security update for github.com/umputun/remark42 (GHSA-4c8j-mgm4-qqvp)

high Tenable Cloud Security Plugin ID 443992

Description

There are packages installed that are affected by a vulnerability referenced in the following CVE:

 - 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. (CVE-2026-48788)

Solution

Update the github.com/umputun/remark42 library and its related packages to version 1.16.0 or later.

See Also

https://github.com/advisories/GHSA-4c8j-mgm4-qqvp

Plugin Details

Severity: High

ID: 443992

Version: Revision 1.2

Type: Local

Family: SCA Checks

Published: 6/26/2026

Updated: 7/2/2026

Supported Sensors: Tenable Cloud Security, Tenable Self-Hosted Container Security

Risk Information

VPR

Risk Factor: Low

Score: 3.9

Percentile: 52.76

Vendor

Vendor Severity: High

CVSS v2

Risk Factor: High

Base Score: 8.5

Temporal Score: 6.3

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:P/A:N

CVSS Score Source: CVE-2026-48788

CVSS v3

Risk Factor: High

Base Score: 8.2

Temporal Score: 7.1

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:N

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

Exploit Ease: No known exploits are available

Patch Publication Date: 6/26/2026

Vulnerability Publication Date: 6/16/2026

Reference Information

CVE: CVE-2026-48788