CVE-2026-15308
Incremental HTMLParser feed() allows CPU-exhaustion DoS via repeated unterminated markup declarations
CVSS Score
0.0
EPSS Score
0.0%
EPSS Percentile
0th
The incremental HTML parser (html.parser.HTMLParser) allows for CPU denial-of-service through repeated unterminated markup declarations when processing uncontrolled data.
| CWE | CWE-400 |
| Vendor | python software foundation |
| Product | cpython |
| Published | Jul 9, 2026 |
| Last Updated | Jul 9, 2026 |
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Affected Versions
Python Software Foundation / CPython
0 < 3.15.0
References
mail.python.org: https://mail.python.org/archives/list/[email protected]/thread/F6453LWKSHKCTWFLCOURWPLETNUIW2Z5/ github.com: https://github.com/python/cpython/pull/153031 github.com: https://github.com/python/cpython/issues/153030 github.com: https://github.com/python/cpython/commit/07efb08123ba9367a7107325adb9d5626dca1ca9 github.com: https://github.com/python/cpython/commit/7933f4bf7131aa4140750f9404f5de0aa2969ced github.com: https://github.com/python/cpython/commit/bcf98ddbc40ec9b3ee87da0124a5660b19b7e606 github.com: https://github.com/python/cpython/commit/e9f92ac0b298292e7ff998e52cb8ccacfb27a0bd openwall.com: http://www.openwall.com/lists/oss-security/2026/07/09/4
Credits
🔍 Edward-x (https://github.com/YLChen-007) Serhiy Storchaka (https://github.com/serhiy-storchaka) Gregory P. Smith (https://github.com/gpshead) Seth Larson (https://github.com/sethmlarson)