PYSEC-2026-1455

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Import Source

https://github.com/pypa/advisory-database/blob/main/vulns/html-sanitizer/PYSEC-2026-1455.yaml

JSON Data

https://api.osv.dev/v1/vulns/PYSEC-2026-1455

Aliases

Published

2026-07-07T11:45:42.091141Z

Modified

2026-07-07T17:47:44.646585963Z

Summary

Arbitrary HTML present after sanitization because of unicode normalization

Details

Impact

If using keep_typographic_whitespace=False (which is the default), the sanitizer normalizes unicode to the NFKC form at the end. Some unicode characters normalize to chevrons; this allows specially crafted HTML to escape sanitization.

Patches

The problem has been fixed in 2.4.2.

Workarounds

Set keep_typographic_whitespace=True explicitly, or normalize to NFKC yourself earlier.

References

Affected packages

PyPI / html-sanitizer

Package

Name: html-sanitizer; View open source insights on deps.dev
Purl: pkg:pypi/html-sanitizer

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Fixed

2.4.2

Affected versions

1.*

1.0.0

1.1.0

1.1.1

1.1.2

1.1.3

1.1.4

1.2.0

1.2.1

1.3.0

1.4.0

1.5.0

1.6.0

1.6.1

1.6.2

1.6.3

1.6.4

1.7.0

1.7.1

1.7.2

1.7.3

1.8.0

1.9.0

1.9.1

1.9.2

1.9.3

2.*

2.0.0

2.1.0

2.2.0

2.3.0

2.3.1

2.4.0

2.4.1

Database specific

source

"https://github.com/pypa/advisory-database/blob/main/vulns/html-sanitizer/PYSEC-2026-1455.yaml"