CVE-2026-91990CWE-770denial-of-service

CVE-2026-91990

High · published September 15, 2026

CVSS v3.1
7.5
EPSS
0%
Percentile
35.6
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
7.5 · HIGH
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS v4.0
8.7 · 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
EPSS
0.00424 · 35.6th percentile
Weakness
CWE-770 · Allocation of Resources Without Limits or Throttling
Published
2026-09-15T20:17Z
References (3)
https://github.com/tornadoweb/tornado/security/advisories/GHSA-8423-8fgw-73vq · [email protected]https://www.vulncheck.com/advisories/tornado-before-6.5.8-memory-amplification-dos-via-multipart · [email protected]https://github.com/tornadoweb/tornado/security/advisories/GHSA-8423-8fgw-73vq · 134c704f-9b21-4f2e-91b3-4a467353bcc0
EPSS history
Timeline
  • 17 SEP 03:33Z
    EPSS moved — → 0%
    epss
  • 15 SEP 15:18Z
    Tornado before 6.5.8 Memory Amplification DoS via multipart
    cvelistv5