CVE-2020-15179: The ScratchSig extension for MediaWiki before version 1.0.1 allows stored Cross-Site Scripting

Q: How do I fix CVE-2020-15179?

scratchsig: upgrade to 1.0.1. Exact commands for each OS are on this page.

Q: Is CVE-2020-15179 being exploited?

CVE-2020-15179 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2020-15179 affect?

CVE-2020-15179 affects scratchsig. Severity is high (CVSS 8.0). The ScratchSig extension for MediaWiki before version 1.0.1 allows stored Cross-Site Scripting. Using tag inside tag, attackers with edit permission can execute scripts on visitors' browser. With MediaWiki JavaScript A

This month

HIGH 8.0UPGRADE

CVE-2020-15179 is a high-severity flaw (CVSS 8.0) affecting scratchsig. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

The ScratchSig extension for MediaWiki before version 1.0.1 allows stored Cross-Site Scripting. Using <script> tag inside <scratchsig> tag, attackers with edit permission can execute scripts on visitors' browser. With MediaWiki JavaScript API, this can potentially lead to privilege escalation and/or account takeover. This has been patched in release 1.0.1. This has already been deployed to all Scratch Wikis. No workarounds exist other than disabl

Why this priority

High severity

A fixed release or distro patch exists.

Risk facts

CVSS score	8.0 (High)
Attack vector	Network (remote)
Attack complexity	High
Privileges needed	Low
User interaction	Required
EPSS exploit chance	1.2% (top 31%)
CISA exploited list	No
Weakness	CWE-79
Published	2020-09-15
Last modified	2026-06-17

Publisher (CNA): GitHub, Inc. · Vendor: scratch-wiki

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2020-09-15 18:15 UTCPublished CVE record published
2026-06-17 02:56 UTCUpdated Record last modified

scratch-wiki scratchsig UPGRADE

Affected: < 1.0.1

Fixed in: 1.0.1

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy scratchsig || rpm -q scratchsig || scratchsig --version

2. UPGRADE to 1.0.1 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade scratchsig

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade scratchsig

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2020-15179?

scratchsig: upgrade to 1.0.1. Exact commands for each OS are on this page.

Is CVE-2020-15179 being exploited?

CVE-2020-15179 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2020-15179 affect?

CVE-2020-15179 affects scratchsig. Severity is high (CVSS 8.0). The ScratchSig extension for MediaWiki before version 1.0.1 allows stored Cross-Site Scripting. Using <script> tag inside <scratchsig> tag, attackers with edit permission can execute scripts on visitors' browser. With MediaWiki JavaScript A

How urgent is CVE-2020-15179?

Priority 45/100. High severity

References

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