CVE-2026-49855

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Source
https://cve.org/CVERecord?id=CVE-2026-49855
Import Source
https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-49855.json
JSON Data
https://api.test.osv.dev/v1/vulns/CVE-2026-49855
Aliases
Downstream
AZL (1)
BELL (1)
CGA (4)
CLSA (2)
DEBIAN (1)
ECHO (1)
MGASA (1)
MINI (9)
OESA (3)
openSUSE (2)
RHSA (3)
RLSA (2)
ROOT (1)
SUSE (13)
UBUNTU (1)
Related
ALSA (2)
openSUSE (2)
SUSE (13)
Published
2026-07-14T20:45:02Z
Modified
2026-10-16T02:36:46Z
Severity
  • 7.5 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
Summary
tornado AsyncHTTPClient accumulates decompressed chunks without size limit (gzip bomb)
Details

Tornado is a Python web framework and asynchronous networking library. Prior to 6.5.6, Tornado gzip decompression routines processed limited-size chunks but did not enforce an overall limit on accumulated decompressed chunks, allowing a malicious server accessed by SimpleAsyncHTTPClient or an HTTPServer configured with decompress_request=True to consume effectively unlimited memory. This issue is fixed in version 6.5.6.

Database specific 
{
    "cna_assigner":  "GitHub_M",
    "cwe_ids":  [
        "CWE-409"
    ],
    "osv_generated_from":  "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/49xxx/CVE-2026-49855.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
aba2569f7ed7a6bdbef816658fb6b7182531b751
Fixed
ff808b33adc52d89a549376a5e3628e92abbc8ff
Database specific
Show details 
{
    "extracted_events":  [
        {
            "range":  [
                {
                    "introduced":  "0"
                },
                {
                    "fixed":  "6.5.6"
                }
            ],
            "source":  "AFFECTED_FIELD",
            "strategy":  "StringRangeExpression"
        },
        {
            "range":  [
                {
                    "fixed":  "ff808b33adc52d89a549376a5e3628e92abbc8ff"
                }
            ],
            "source":  "REFERENCES_COMMIT"
        }
    ]
}

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
v6.5.5

Database specific

source 
"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-49855.json"