CVE-2020-15275
malicious SVG attachment causing stored XSS vulnerability in MoinMoin
CVE-2020-15275 is a high vulnerability (CVSS 8.7) in Moinmo Moinmoin, published November 9, 2020. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.75%, the 77th percentile. Fixed in moin 1.9.11.
MoinMoin is a wiki engine. In MoinMoin before version 1.9.11, 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. 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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- Required
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
malicious SVG attachment causing stored XSS vulnerability in MoinMoin
MoinMoin is a wiki engine. In MoinMoin before version 1.9.11, 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. 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.
- Record
CVE-2020-15275- CVSS 3.1
- 8.7 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
EUVDEUVD-2020-0113
MoinMoin is a wiki engine. In MoinMoin before version 1.9.11, 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. 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.
- Record
EUVD-2020-0113- CVSS 3.1
- 8.7 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-4q96-6xhq-ff43
malicious SVG attachment causing stored XSS vulnerability
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 [email protected].
Credits
This vulnerability was discovered by:
Catarina Leite from the Checkmarx SCA AppSec team
- Record
GHSA-4q96-6xhq-ff43- CVSS 4.0
- 6.4 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N - CVSS 3.1
- 8.7 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
NVD
MoinMoin is a wiki engine. In MoinMoin before version 1.9.11, 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. 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.
- Record
CVE-2020-15275- CVSS 3.1
- 8.7 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N - CVSS 3.1
- 5.4 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N - CVSS 2.0
- 3.5 Low
AV:N/AC:M/Au:S/C:N/I:P/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
OSV
MoinMoin is a wiki engine. In MoinMoin before version 1.9.11, 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. 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.
- Record
CVE-2020-15275- CVSS 3.1
- 5.4 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N - Updated
- 2026-11-02
OSVGHSA-4q96-6xhq-ff43
malicious SVG attachment causing stored XSS vulnerability
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 [email protected].
Credits
This vulnerability was discovered by:
Catarina Leite from the Checkmarx SCA AppSec team
- Record
GHSA-4q96-6xhq-ff43- CVSS 4.0
- 6.4 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N - CVSS 3.1
- 8.7 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
Show 5 moreShow less
OSVUBUNTU-CVE-2020-15275
MoinMoin is a wiki engine. In MoinMoin before version 1.9.11, 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. 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.
- Record
UBUNTU-CVE-2020-15275- CVSS 3.1
- 5.4 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N - CVSS 3.1
- 8.7 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N - Updated
- 2026-11-02
OSVopenSUSE-SU-2020:1966-1 No score
Security update for moinmoin-wiki
This update for moinmoin-wiki fixes the following issues:
- update to version 1.9.11: CVE-2020-25074 (boo#1178744): fix remote code execution via cache action CVE-2020-15275 (boo#1178745): fix malicious SVG attachment causing stored XSS vulnerability
- Record
openSUSE-SU-2020:1966-1- Updated
- 2026-11-02
OSVopenSUSE-SU-2020:1998-1 No score
Security update for moinmoin-wiki
This update for moinmoin-wiki fixes the following issues:
- update to version 1.9.11: CVE-2020-25074 (boo#1178744): fix remote code execution via cache action CVE-2020-15275 (boo#1178745): fix malicious SVG attachment causing stored XSS vulnerability
This update was imported from the openSUSE:Leap:15.2:Update update project.
- Record
openSUSE-SU-2020:1998-1- Updated
- 2026-11-02
OSVPYSEC-2020-241 No score
MoinMoin is a wiki engine. In MoinMoin before version 1.9.11, 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. 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.
- Record
PYSEC-2020-241- Updated
- 2026-11-02
OSVUSN-4629-1 No score
moin vulnerabilities
Michael Chapman discovered that MoinMoin incorrectly handled certain cache actions. An attacker could possibly use this issue to execute arbitrary code. (CVE-2020-25074)
Catarina Leite discovered that MoinMoin incorrectly handled certain SVG files. An attacker could possibly use this issue to execute arbitrary code. (CVE-2020-15275)
- Record
USN-4629-1- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
moinPyPI |
before 1.9.11 | 1.9.11 |
moinDebian:9 |
before 1.9.9-1+deb9u2, plus listed versions 1.9.9-11.9.9-1+deb9u1 |
1.9.9-1+deb9u2 |
moinDebian:10 |
before 1.9.9-1+deb10u1 | 1.9.9-1+deb10u1 |
moinPyPI |
before 1.9.11, plus listed versions 1.8.41.8.51.8.61.8.71.9.0 Show 10 moreShow less1.9.11.9.101.9.21.9.31.9.41.9.51.9.61.9.71.9.81.9.9 |
1.9.11 |
moinUbuntu:16.04:LTS |
before 1.9.8-1ubuntu1.16.04.3, plus listed versions 1.9.7-2ubuntu31.9.8-1ubuntu11.9.8-1ubuntu1.16.04.11.9.8-1ubuntu1.16.04.2 |
1.9.8-1ubuntu1.16.04.3 |
moinUbuntu:18.04:LTS |
before 1.9.9-1ubuntu1.2, plus listed versions 1.9.9-1ubuntu11.9.9-1ubuntu1.1 |
1.9.9-1ubuntu1.2 |
moinmoin-wikiopenSUSE:Leap 15.2 |
before 1.9.11-lp152.3.3.1 | 1.9.11-lp152.3.3.1 |
moinmoin-wikiSUSE:Package Hub 15 SP2 |
before 1.9.11-bp152.4.3.1 | 1.9.11-bp152.4.3.1 |
History
| When | Changed | Sources |
|---|---|---|
| 2026-11-03 | aliases | EUVD |
| 2026-11-02 | created | CVE List, GitHub Advisories, NVD, OSV |
References
github.com/moinwiki/moin-1.9/security/advisories/GHSA-4q96-6xhq-ff43
advisory.checkmarx.net/advisory/CX-2020-4285
nvd.nist.gov/vuln/detail/CVE-2020-15275
Show 14 moreShow less
pypi.org/project/moin
ubuntu.com/security/CVE-2020-15275
cve.org/CVERecord?id=CVE-2020-15275
lists.opensuse.org/archives/list/[email protected]/thread/ZWQ3H4AUJA2F3ISKMWL6QTCZID5AYFKR
bugzilla.suse.com/1178744
suse.com/security/cve/CVE-2020-15275