CVE-2026-82397
Tornado: Urlencoded body parsing omits max_num_fields, so one request can stall the event loop
En bref
- Source
- NVD
- EPSS
- EPSS 0.35 % · centile 28 ()
- État
- PUBLISHED
- Publiée
- Mise à jour
- Attribuée par
- GitHub_M
- Statut NVD
- Deferred
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.
Faiblesses (CWE)
- CWE-400 — Consommation de ressources non maîtrisée (déni de service)
- CWE-1284 — Validation incorrecte d'une quantité spécifiée en entrée
Références
Scores
| Version | Score | Vecteur | Évalué par |
|---|---|---|---|
| CVSS 3.1 | HIGH 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | GitHub_M |
| CVSS 3.1 | HIGH 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | NVD · security-advisories@github.com (Secondary) |
Avis
- GHSA-mpf4-983q-p7j4 — Tornado: Urlencoded body parsing omits max_num_fields, so one request can stall the event loop
- PYSEC-2026-3928 — Tornado: Urlencoded body parsing omits max_num_fields, so one request can stall the event loop
Références européennes
- ENISA EUVD · EUVD-2026-68892
- GCVE · GCVE-0-2026-82397
Avis du CERT-FR
- CERTFR-2026-AVI-1233 — Multiples vulnérabilités dans les produits IBM · cert.ssi.gouv.fr
Produits affectés
| Produit | Versions |
|---|---|
| tornadoweb · tornado | affected < 6.5.8 |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| CERT-FR (ANSSI) | Licence Ouverte / Etalab 2.0 |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |