---
id: CVE-2020-15275
aliases:
  - GHSA-4q96-6xhq-ff43
  - PYSEC-2020-241
title: malicious SVG attachment causing stored XSS vulnerability
summary: malicious SVG attachment causing stored XSS vulnerability
severity: high
cvss: 8.7
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N'
vendor: moin
product: moin
ecosystem: pip
affected:
  - moin < 1.9.11
patched:
  - moin 1.9.11
published: '2020-11-11'
updated: '2026-07-08'
source: OSV
sourceUrl: 'https://osv.dev/vulnerability/GHSA-4q96-6xhq-ff43'
references:
  - url: >-
      https://github.com/moinwiki/moin-1.9/security/advisories/GHSA-4q96-6xhq-ff43
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2020-15275'
  - url: >-
      https://github.com/moinwiki/moin-1.9/commit/31de9139d0aabc171e94032168399b4a0b2a88a2
  - url: 'https://advisory.checkmarx.net/advisory/CX-2020-4285'
  - url: 'https://github.com/moinwiki/moin-1.9'
  - url: 'https://github.com/moinwiki/moin-1.9/releases/tag/1.9.11'
  - url: >-
      https://github.com/pypa/advisory-database/tree/main/vulns/moin/PYSEC-2020-241.yaml
  - url: 'https://pypi.org/project/moin'
tags:
  - osv
  - pip
epss: 0.01746
epssPercentile: 0.76831
ingestedAt: '2026-07-08T18:25:45.522Z'
---

## Overview

### Impact
An attacker with `write` permissions can upload an SVG file that contains malicious javascript. This javascript will be executed in a user's browser when the user is viewing that SVG file on the wiki.

### Patches
Users are strongly advised to upgrade to a patched version.

MoinMoin Wiki 1.9.11 has the necessary fixes and also contains other important fixes.

### Workarounds
It is not advised to work around this, but to upgrade MoinMoin to a patched version.

That said, a work around via a Content Security Policy in the web server might be possible.

Also, it is of course helpful if you give `write` permissions (which include uploading attachments) only to trusted users.

### For more information
If you have any questions or comments about this advisory, email me at [twaldmann@thinkmo.de](mailto:twaldmann@thinkmo.de).

### Credits

This vulnerability was discovered by:

Catarina Leite from the Checkmarx SCA AppSec team

## Affected packages

- `moin < 1.9.11`

## Remediation

Upgrade to a patched release:

- `moin 1.9.11`