CVE-2026-82397Patch

LOWCVSS 7.5 · HIGH

Signal is active with 1 mentions in latest observed window

Immediate actions

Patch affected systems immediately

Recommended action window: Monitor and triage in normal cycle

NVD description

Tornado is a Python web framework and asynchronous networking library. Prior to 6.5.8, Tornado parses application/x-www-form-urlencoded request bodies with urllib.parse.parse_qs in tornado/escape.py without passing max_num_fields. RequestHandler._execute in tornado/web.py parses the body before handler dispatch through HTTPServerRequest._parse_body and parse_body_arguments in tornado/httputil.py, so an unauthenticated request body containing millions of separator-delimited fields can synchronously stall the single-threaded event loop and delay every connection. The body is bounded only by max_buffer_size, which defaults to 104857600 bytes. This issue is fixed in version 6.5.8.

Back to dashboard

0.5/ 10 priority

Sources & remediation

Other references

Weakness type (CWE)

CWE-400CWE-1284

Priority

LOW

Exploitation

NONE

PoC

NONE

Patch

AVAILABLE

Momentum

NONE

Threat summary

Patch or workaround signal is available
1 mentions across 1 observed day

What's happening

Patch or workaround mentioned in 1 signal
Technical details provided in 1 signal
1 total mentions across 1 day

Deep dive

Activity timeline1 mentions / 1d

Signal classification1 categories

Patch

1100.0%

Full discourse1 post

Upwind Security MDR@UpwindMDR46d
Patch
🚨High - Tornado URL-Encoded Body Field Explosion DoS (CVE-2026-82397) Tornado <6.5.8 parses application/x-www-form-urlencoded bodies via urllib.parse.parse_qs without max_num_fields, allowing unauthenticated requests with millions of &-delimited fields to trigger synchronous parsing on the single-threaded IOLoop. Impact: event loop stall / denial of service. 👉Affected: tornado < 6.5.8 | Upgrade to 6.5.8
Post summary
The announcement highlights a new DoS vulnerability in Tornado <6.5.8 and recommends upgrading to v6.5.8 to patch the issue. It provides technical details of the flaw but no exploit evidence or active usage reports.
0000072
303 followersView on X

Explore more

Back to dashboard