CVE-2026-31958

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Source
https://cve.org/CVERecord?id=CVE-2026-31958
Import Source
https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-31958.json
JSON Data
https://api.test.osv.dev/v1/vulns/CVE-2026-31958
Aliases
Downstream
BELL (1)
CGA (13)
CLEANSTART (15)
CLSA (1)
DEBIAN (1)
ECHO (1)
MGASA (1)
MINI (4)
OESA (6)
openSUSE (4)
RHSA (14)
RLSA (5)
ROOT (1)
SUSE (22)
UBUNTU (1)
Related
ALSA (5)
openSUSE (4)
SUSE (21)
Published
2026-03-11T19:27:23Z
Modified
2026-08-12T03:30:16Z
Severity
  • 8.7 (High) CVSS_V4 - 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 CVSS Calculator
Summary
Tornado has a DoS due to too many multipart parts
Details

Tornado is a Python web framework and asynchronous networking library. In versions of Tornado prior to 6.5.5, the only limit on the number of parts in multipart/form-data is the max_body_size setting (default 100MB). Since parsing occurs synchronously on the main thread, this creates the possibility of denial-of-service due to the cost of parsing very large multipart bodies with many parts. This vulnerability is fixed in 6.5.5.

Database specific 
{
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
        "CWE-400"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31958.json"
}
References

Affected packages

Git / github.com/tornadoweb/tornado

Affected ranges

Type
GIT
Repo
https://github.com/tornadoweb/tornado
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Fixed
7d6465056ceb7a054b3f64cf1c18271753b10482
Database specific
Show details 
{
    "cpe": "cpe:2.3:a:tornadoweb:tornado:*:*:*:*:*:*:*:*",
    "extracted_events": [
        {
            "introduced": "0"
        },
        {
            "fixed": "6.5.5"
        }
    ],
    "source": [
        "AFFECTED_FIELD",
        "CPE_RANGE"
    ]
}

Affected versions

v1.*
v1.0.0
v1.1.0
v1.2.0
v2.*
v2.0.0
v2.1.0
v2.1.1
v2.2.0
v2.3.0
v3.*
v3.0.0
v3.0.1
v3.1.0
v3.2.0
v3.2.0b1
v3.2.0b2
v4.*
v4.0.0
v4.0.0b1
v4.0.0b2
v4.0.0b3
v4.1.0
v4.1.0b1
v4.1.0b2
v4.2.0
v4.2.0b1
v4.3.0
v4.3.0b1
v4.3.0b2
v4.4.0
v4.4.0b1
v4.4.1
v4.5.0
v4.5.1
v5.*
v5.0.0
v5.1.0
v6.*
v6.0.0
v6.0.0b1
v6.1.0
v6.1.0b1
v6.1.0b2
v6.2.0
v6.2.0b1
v6.2.0b2
v6.3.0
v6.3.0b1
v6.3.1
v6.4.0
v6.4.0b1
v6.4.1
v6.5.0
v6.5.0b1
v6.5.1
v6.5.2
v6.5.3
v6.5.4

Database specific

source 
"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-31958.json"