Vulnerability details

CVE-2026-91990

tornadoweb tornado

Tornado before 6.5.8 Memory Amplification DoS via multipart

CVSS 4.0
8.7High

Official description

Tornado before 6.5.8 contains a memory amplification vulnerability in parse_multipart_form_data that splits multipart data before validating the max_parts limit. Attackers can send crafted multipart requests with many parts to create large transient lists, exhausting server memory and causing denial of service.

CVSS scores

ScoreVersionSourceVector
8.7High 4.0 CVEProject cvelistV5 (CNA) (VulnCheck) CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
7.5High 3.1 CVEProject cvelistV5 (CNA) (VulnCheck) CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products

VendorProductVersionsSource
tornadoweb tornado v < 6.5.8 CVEProject cvelistV5 (CNA)

References and advisories

2
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Details

Published
2026-09-15
Last updated
2026-09-15
State
Published
Assigner (CNA)
VulnCheck

Exploit prediction (EPSS)

0.42%
Probability of exploitation in 30 days
36.9%
Percentile (among all CVEs)

SSVC assessment (CISA)

Automatable
Yes
Exploitation
Proof of concept
Technical impact
Partial

Weaknesses (CWE)

  • CWE-770
    Allocation of Resources Without Limits or Throttling