CVE-2026-105830: league/commonmark: Quadratic-time denial of service in the GitHub Flavored Markdown Table extension block-start scan

high Affects league/commonmark. Feed 2026.10.29.1, updated 2026-10-28; published 2026-09-30; advisory modified 2026-10-09.

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

Package: league/commonmark Composer
Affected versions: >=2.0.0 and <2.10.2
Fixed in: 2.10.2
Severity: high CVSS 7.5
Exploitation: not on CISA KEV · EPSS 0% (30.5th percentile)
Published: 2026-09-30
Source: osv.dev

References

CWE-400 CWE-407

NVD record league/commonmark advisories

Am I affected?

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# PHP projects (recommended)
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CVE-2026-86428 high league/commonmark: Denial of service via distinctly-named attributes in the Attributes ext same package: league/commonmark