CVE-2026-15308

The incremental HTML parser (html.parser.HTMLParser) allows for CPU denial-of-service through repeated unterminated markup declarations when processing uncontrolled data.

  • Published Jul 9, 2026
  • CVSS 8.7 high
  • 0.6% chance of exploitation in the next 30 days (EPSS)
  • A fix is available

Affected software

In the news

CVE-2026-15308 at the National Vulnerability Database