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HIGH

CVE-2026-91990

CVSS v3

7.5

HIGH

EPSS Score

0.5 %

exploit probability, as of 2026-09-28

CISA KEV

No

known exploited

Exploitation

—

SSVC status

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.

Technical details

Published
2026-09-15
Last Modified
2026-09-16

Frequently asked questions

What is CVE-2026-91990?

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.

Is CVE-2026-91990 actively exploited?

Active exploitation of CVE-2026-91990 has not been confirmed. Its EPSS score was 0.5% on 2026-09-28, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2026-91990?

CVE-2026-91990 has a CVSS v3 base score of 7.5 (HIGH severity).

Is CVE-2026-91990 affecting your environment?

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