What’s Vulnerable › Vulnerabilities

CVE-2017-16876

• Severity: medium (CVSS 6.1 v3.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 2.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2017-12-29 · updated 2026-06-17
• Weakness: CWE-79

Description

Cross-site scripting (XSS) vulnerability in the _keyify function in mistune.py in Mistune before 0.8.1 allows remote attackers to inject arbitrary web script or HTML by leveraging failure to escape the "key" argument.

Affected products

• Fedoraproject Fedora: 26
• lepture mistune: before 0.8.1 — fixed in 0.8.1

How to fix

Upgrade to a fixed version: lepture mistune 0.8.1. Check the vendor advisory for mitigations.

References

• https://bugzilla.redhat.com/show_bug.cgi?id=1524596
• https://github.com/lepture/mistune/blob/master/CHANGES.rst
• https://github.com/lepture/mistune/commit/5f06d724bc05580e7f203db2d4a4905fc1127f98
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/NUR3GMHQBMA3UC4PFMCK6GCLOQC4LQQC/
• https://bugzilla.redhat.com/show_bug.cgi?id=1524596
• https://github.com/lepture/mistune/blob/master/CHANGES.rst
• https://github.com/lepture/mistune/commit/5f06d724bc05580e7f203db2d4a4905fc1127f98
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/NUR3GMHQBMA3UC4PFMCK6GCLOQC4LQQC/

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