Vulnerability Description
unicodedata.normalize() can take excessive CPU time when processing specially crafted Unicode input containing long runs of combining characters with alternating Canonical Combining Class values. This affects all normalization forms.
Related Weaknesses (CWE)
References
- https://github.com/python/cpython/commit/6b505d1f41f8f3ea0fe5a4786d3a8fff1875cfc
- https://github.com/python/cpython/commit/90748760d38ca3ac5fc6788a69becab905c9559
- https://github.com/python/cpython/commit/991224b1e8311c85f198f6dd8208bf8cff7fc26
- https://github.com/python/cpython/commit/ba785b88add96acbf403d65cb157fb2743a33a3
- https://github.com/python/cpython/commit/c5512bd7c1dc28055660565275012766941d306
- https://github.com/python/cpython/commit/d3ab945af25b28dfe13ac6cb40c124a01b33ce1
- https://github.com/python/cpython/commit/db744c0776c1d5dd11aaa70eff2a6993c408bac
- https://github.com/python/cpython/commit/e322a1857084d521f79f45181b776f62e6acfc2
- https://github.com/python/cpython/issues/149079
- https://github.com/python/cpython/pull/149080
- https://mail.python.org/archives/list/[email protected]/thread/PP5HB4
- http://www.openwall.com/lists/oss-security/2026/06/03/15
FAQ
What is CVE-2026-3276?
CVE-2026-3276 is a documented vulnerability. unicodedata.normalize() can take excessive CPU time when processing specially crafted Unicode input containing long runs of combining characters with alternating Canonical Combining Class values. This...
How severe is CVE-2026-3276?
CVSS scoring is not yet available for CVE-2026-3276. Check NVD for updates.
Is there a patch for CVE-2026-3276?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.