league/commonmark vulnerabilities

Highly-extensible PHP Markdown parser which fully supports the CommonMark spec and GitHub-Flavored Markdown (GFM)

Registry
Composer
Latest
2.10.4
License
BSD-3-Clause

18 known advisories

The latest version, 2.10.4, is not affected by any of them. Projects on older versions may be.

Update to the latest version:composer require league/commonmark:^2.10.4

Security advisories for league/commonmark

  • MediumGHSA-97jj-33gv-5xf930 Sept 2026

    league/commonmark: DisallowedRawHtml bypassed when a disallowed tag name ends the raw-HTML literal

    Affected
    >=1.3.0 <2.10.2
    Fixed in
    2.10.2
  • HighGHSA-3q6v-r5mr-hxv830 Sept 2026

    league/commonmark: Quadratic-time denial of service in the GitHub Flavored Markdown Table extension block-start scan

    Affected
    >=2.0.0 <2.10.2
    Fixed in
    2.10.2
  • HighGHSA-8rr7-cvq3-gmfh1 Sept 2026

    league/commonmark: Denial of service via distinctly-named attributes in the Attributes extension

    Affected
    >=1.5.0 <2.10.0
    Fixed in
    2.10.0
  • HighGHSA-jjv6-8j6v-6j521 Sept 2026

    league/commonmark: Denial of service in the SmartPunct and Attributes extensions

    Affected
    >=1.5.0 <2.9.1
    Fixed in
    2.9.1
  • HighGHSA-f8fg-pg57-v4j81 Sept 2026

    league/commonmark XSS: `on*` event-handler filter in `AttributesExtension` bypassed with a U+000C form feed

    Affected
    >=2.7.0 <2.9.1
    Fixed in
    2.9.1
  • HighGHSA-j8pm-gj4c-rq4x1 Sept 2026

    league/commonmark: Denial of service via crafted code fences, reference links, and emphasis delimiters

    Affected
    >=0.6.0 <2.9.1
    Fixed in
    2.9.1
  • MediumGHSA-mj63-m3rc-8ppr6 Aug 2026

    league/commonmark: Denial of service via deeply nested XML output

    Affected
    >=2.0.0 <2.9.0
    Fixed in
    2.9.0
  • HighGHSA-mh25-x5hq-wrqp6 Aug 2026

    league/commonmark: Denial of service via colliding heading slugs

    Affected
    >=2.0.0 <2.9.0
    Fixed in
    2.9.0
  • HighGHSA-jfm3-95jq-q3rf6 Aug 2026

    league/commonmark: Denial of service via duplicate footnote definitions

    Affected
    >=1.5.0 <2.9.0
    Fixed in
    2.9.0
  • HighGHSA-g2gp-3wwq-f4ph6 Aug 2026

    league/commonmark: Denial of service via adjacent inline attribute blocks

    Affected
    >=1.5.0 <2.9.0
    Fixed in
    2.9.0
  • HighGHSA-2q4p-g7hv-5rgv6 Aug 2026

    league/commonmark: Quadratic-time denial of service when parsing crafted Markdown

    Affected
    >=0.6.0 <2.9.0
    Fixed in
    2.9.0
  • MediumGHSA-29pj-957v-52mc6 Aug 2026

    league/commonmark: AttributesExtension href/src unsafe-link filter bypass via embedded control bytes

    Affected
    >=1.5.0 <2.9.0
    Fixed in
    2.9.0
  • MediumGHSA-hh8v-hgvp-g3f519 Mar 2026

    league/commonmark has an embed extension allowed_domains bypass

    Affected
    >=2.3.0 <2.8.2
    Fixed in
    2.8.2
  • MediumGHSA-4v6x-c7xx-hw9f6 Mar 2026

    CommonMark has DisallowedRawHtml extension bypass via whitespace in HTML tag names

    Affected
    >=2.0.0 <2.8.1
    Fixed in
    2.8.1
  • MediumGHSA-3527-qv2q-pfvx5 May 2025

    league/commonmark contains a XSS vulnerability in Attributes extension

    Affected
    >=1.5.0 <2.7.0
    Fixed in
    2.7.0
  • HighGHSA-c2pc-g5qf-rfrf9 Dec 2024

    league/commonmark's quadratic complexity bugs may lead to a denial of service

    Affected
    <2.6.0
    Fixed in
    2.6.0
  • MediumGHSA-qx76-c53f-5c7q14 May 2022

    PHP League CommonMark vulnerable to Cross-Site Scripting (XSS)

    Affected
    >=0.15.6 <0.18.1
    Fixed in
    0.18.1
  • MediumGHSA-3v43-877x-qgmq17 Sept 2019

    Moderate severity vulnerability that affects league/commonmark

    Affected
    <0.18.3
    Fixed in
    0.18.3

Which of your client projects still run an old league/commonmark?

NPMscan reads the composer.lock in every GitHub repo you pick and checks each installed version against these advisories, including the packages your packages pull in. Each finding comes with the command that fixes it.

Other Composer packages

Advisory data from OSV.dev (opens OSV.dev in a new tab), refreshed daily. Package details from the Composer registry.