5.4
MEDIUM CVSS 3.1
CVE-2026-53962
Discourse: Insufficient SVG sanitization logic
Description

Discourse is an open-source discussion platform. Prior to 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5, insufficient SVG sanitization in upload and user avatar handling could lead to cross-site scripting when a user visited specific URLs that are not normally part of community browsing. This issue is fixed in versions 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5.

INFO

Published Date :

July 9, 2026, 10:17 p.m.

Last Modified :

July 9, 2026, 10:17 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-53962 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 MEDIUM [email protected]
Solution
Update Discourse to a fixed version to prevent cross-site scripting vulnerabilities.
  • Update Discourse to version 2026.6.0 or later.
  • Apply patches for versions 2026.5.1, 2026.4.2, or 2026.1.5.
  • Sanitize all user-uploaded SVG files thoroughly.
  • Validate all user-uploaded avatar data.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-53962 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-53962 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-53962 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-53962 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Jul. 09, 2026

    Action Type Old Value New Value
    Added Affected [{'vendor': 'discourse', 'product': 'discourse', 'versions': [{'status': 'affected', 'version': '>= 2026.1.0-latest, < 2026.1.5'}, {'status': 'affected', 'version': '>= 2026.4.0-latest, < 2026.4.2'}, {'status': 'affected', 'version': '>= 2026.5.0-latest, < 2026.5.1'}]}]
    Added Description Discourse is an open-source discussion platform. Prior to 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5, insufficient SVG sanitization in upload and user avatar handling could lead to cross-site scripting when a user visited specific URLs that are not normally part of community browsing. This issue is fixed in versions 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5.
    Added CVSS V3.1 AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
    Added CWE CWE-79
    Added Reference https://github.com/discourse/discourse/commit/3ee8343cd7f00d59d8513bee0a12e02d50bfc358
    Added Reference https://github.com/discourse/discourse/commit/810c2715799fd08b06fd6ffc664d9562fe9ea6ff
    Added Reference https://github.com/discourse/discourse/commit/92a699d89b84685b6fdd63cd0d0e371793c69dad
    Added Reference https://github.com/discourse/discourse/commit/b8ceb49f4ba52257be30eb3c2ce51a5bf03be5fe
    Added Reference https://github.com/discourse/discourse/releases/tag/v2026.1.5
    Added Reference https://github.com/discourse/discourse/releases/tag/v2026.4.2
    Added Reference https://github.com/discourse/discourse/releases/tag/v2026.5.1
    Added Reference https://github.com/discourse/discourse/releases/tag/v2026.6.0
    Added Reference https://github.com/discourse/discourse/security/advisories/GHSA-jmcf-3367-78vv
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.