CVE-2026-115349
Mistune 3.0.0 before 3.3.0 Denial of Service via Nested Bracket Parsing
CVSS Score
7.5
EPSS Score
0.0%
EPSS Percentile
0th
Mistune from 3.0.0 before 3.3.0 contains an algorithmic complexity denial of service vulnerability in the parse_link_text function in src/mistune/helpers.py. Attackers can submit markdown with deeply nested square brackets triggering quadratic parsing time, exhausting server CPU with small crafted requests.
| CWE | CWE-1333 |
| Vendor | lepture |
| Product | mistune |
| Published | Oct 22, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High
Affected Versions
lepture / mistune
3.0.0 < 3.3.0
References
Credits
🔍 dapickle