CVE-2026-15308
Incremental HTMLParser feed() allows CPU-exhaustion DoS via repeated unterminated markup declarations
- State
- Published
- Severity
- 8.7 High
- Published
- Jul 9, 2026
- Updated
- Aug 13, 2026
- Reserved
- Jul 9, 2026
Description
The incremental HTML parser (html.parser.HTMLParser) allows for CPU denial-of-service through repeated unterminated markup declarations when processing uncontrolled data.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 8.7 High | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N | PSF |
Weaknesses
Affected Products
| Product | Versions |
|---|---|
CPythonPython Software Foundation |
|
References
- https://mail.python.org/archives/list/security-announce@python.org/thread/F6453LWKSHKCTWFLCOURWPLETNUIW2Z5/vendor-advisory
- https://github.com/python/cpython/pull/153031patch
- https://github.com/python/cpython/issues/153030issue-tracking
- https://github.com/python/cpython/commit/07efb08123ba9367a7107325adb9d5626dca1ca9patch
- https://github.com/python/cpython/commit/7933f4bf7131aa4140750f9404f5de0aa2969cedpatch
- https://github.com/python/cpython/commit/bcf98ddbc40ec9b3ee87da0124a5660b19b7e606patch
- https://github.com/python/cpython/commit/e9f92ac0b298292e7ff998e52cb8ccacfb27a0bdpatch
- https://github.com/python/cpython/commit/785df8f743800661961528970f8598edcd291c14patch
- https://github.com/python/cpython/commit/1e7956f1a722df9aabc509c30f8fbdc3a2b4fdc7patch
- https://github.com/python/cpython/commit/c2390b9376e35a701ed3acc597b8fc87546c9b00patch
- http://www.openwall.com/lists/oss-security/2026/07/09/4
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