CVE-2026-1285: Django has Inefficient Algorithmic Complexity

An issue was discovered in 6.0 before 6.0.2, 5.2 before 5.2.11, and 4.2 before 4.2.28.

django.utils.text.Truncator.chars() and Truncator.words() methods (with html=True) and the truncatechars_html and truncatewords_html template filters allow a remote attacker to cause a potential denial-of-service via crafted inputs containing a large number of unmatched HTML end tags. Earlier, unsupported Django series (such as 5.0.x, 4.1.x, and 3.2.x) were not evaluated and may also be affected.

Django would like to thank Seokchan Yoon for reporting this issue.