CVE-2026-3276
Potential DoS via quadratic complexity in unicodedata.normalize()
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Fix
- Fixed in 3.10.21, 3.11.16, 3.12.14, 3.13.14, 3.14.6, and 1 more
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
CISA's decision points: whether it is exploited, whether attacks can be automated, and how much control an attacker gets. Assessed (SSVC 2.0.3).What do these mean? →
- Exploitation: none
- Automatable: no
- Technical impact: partial
Summary
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.
Timeline
- CVE published
- CISA SSVC assessment
Exploitation: none · Automatable: no · Technical impact: partial
- Record last updated
Affected versions
- Python Software Foundation CPython
fixed in 3.10.21; From 3.11.0 · fixed in 3.11.16; From 3.12.0 · fixed in 3.12.14; From 3.13.0 · fixed in 3.13.14; From 3.14.0 · fixed in 3.14.6; From 3.15.0a1 · fixed in 3.15.0b2