What is CVE-2018-20583?

CVE-2018-20583 is a medium-severity vulnerability in Thephpleague Commonmark, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2018-12-30.

How severe is CVE-2018-20583?

Medium severity. CVSS v3 base score is 6.1 out of 10.

Is CVE-2018-20583 known to be exploited?

1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

XSS in Thephpleague Commonmark

CVE-2018-20583

Cross-site scripting (XSS) vulnerability in the PHP League CommonMark library versions 0.15.6 through 0.18.x before 0.18.1 allows remote attackers to insert unsafe URLs into HTML (even if allow_unsafe_links is false) via a newline characte…

Vulnerability class: XSS (Cross-Site Scripting)

EPSS: 0.016 (73.2th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.

Affected products

Thephpleague Commonmark
N/a — versions n/a

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

Public proof-of-concept exploits

ARPSyndicate/cvemon

References

cve@mitre.org (Third Party Advisory, x_refsource_MISC, Release Notes)
cve@mitre.org (Exploit, Third Party Advisory, x_refsource_MISC)
cve@mitre.org (Third Party Advisory, x_refsource_MISC, Release Notes)

Frequently asked questions

What is CVE-2018-20583?: CVE-2018-20583 is a medium-severity vulnerability in Thephpleague Commonmark, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2018-12-30.
How severe is CVE-2018-20583?: Medium severity. CVSS v3 base score is 6.1 out of 10.
Is CVE-2018-20583 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.