How severe is CVE-2017-16876?

CVE-2017-16876 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2017-16876 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (81st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2017-16876?

CVE-2017-16876 primarily affects Mistune Project Mistune. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2017-16876?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2017-16876 published?

CVE-2017-16876 was published on 2017-12-29 and last updated on 2026-06-17.

CVE-2017-16876

CVE-2017-16876 is a medium-severity vulnerability in Mistune Project Mistune with a CVSS 3.x base score of 6.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-79.

Key facts

Severity: Medium (CVSS 3.x base score 6.1)
CVSS v2: 4.3
EPSS exploit prediction: 2% (81st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-79
Affected product: Mistune Project Mistune
Published: 2017-12-29
Last modified: 2026-06-17

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.

Frequently asked questions

What is CVE-2017-16876?: 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.
How severe is CVE-2017-16876?: CVE-2017-16876 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2017-16876 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (81st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2017-16876?: CVE-2017-16876 primarily affects Mistune Project Mistune. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2017-16876?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2017-16876 published?: CVE-2017-16876 was published on 2017-12-29 and last updated on 2026-06-17.

References

Affected products (2)

cpe:2.3:a:mistune_project:mistune:*:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:26:*:*:*:*:*:*:*

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