CVE-2026-49854

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Source
https://cve.org/CVERecord?id=CVE-2026-49854
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-49854.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-49854
Aliases
Downstream
Related
Published
2026-07-14T20:43:03.977Z
Modified
2026-08-12T16:09:42.426605Z
Severity
  • 5.3 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N CVSS Calculator
Summary
Tornado: Out-of-bounds memory access in C extension
Details

Tornado is a Python web framework and asynchronous networking library. Prior to 6.5.6, the optional native extension tornado.speedups implemented websocket_mask without validating that the mask argument is exactly four bytes, allowing the C function to read up to three bytes beyond the provided buffer when reached through Tornado XSRF token decoding with the native extension active. This issue is fixed in version 6.5.6.

Database specific 
{
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/49xxx/CVE-2026-49854.json",
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
        "CWE-126"
    ]
}
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
96dc88c2a05705287856b2cd6b4b4034f9a6aaac
Fixed
aba2569f7ed7a6bdbef816658fb6b7182531b751
Database specific
Show details 
{
    "source": [
        "AFFECTED_FIELD",
        "REFERENCES"
    ],
    "extracted_events": [
        {
            "introduced": "0"
        },
        {
            "fixed": "6.5.6"
        }
    ]
}

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

vanir_signatures 
[
    {
        "signature_type": "Line",
        "deprecated": false,
        "digest": {
            "line_hashes": [
                "69152222405742774919419822103616556764",
                "136855752769639111195829491552343707515",
                "134347400310488647173644052578299431655",
                "210177054561993402163448072370861998577",
                "150939033318264099469803118498694840174",
                "44978230418197210418665842375245754147",
                "323146380916282484097659453254075638852",
                "307980670742470197743589870197436305892",
                "124178985234500210554954807861892481501",
                "298806864955955245326434189918260987010",
                "302903515213188644053282803837467549708",
                "101969162367672096027900378735187729983",
                "256314579132342879389861526417842574747",
                "291794480282353333693226023903022155497",
                "121449369112449939788047203619823141368",
                "249700224388221785793076185166567228666",
                "87384731639233814664436377488334525344",
                "153839714621802045139657011135592662135",
                "310804282497436997995225171678919195455",
                "75272632965016608641446228541415758475",
                "153681437051003746646398433615045494797",
                "175905540179349918679794070005052282435",
                "26968051157052855385335253704642673240",
                "43711998099368376768314740067028468356",
                "317662269419033308372569101368678457740",
                "286658246623988026070709271309776679120",
                "150548722638703707528716594560945333841",
                "1796113314753932800691218463121619100",
                "114807482589785217419374889353565149788",
                "265015882673733507258110704015923534775",
                "143034310535923429762763424054448685063",
                "329305966719808210187811916370459179288",
                "2897493504112618498718845741387139714",
                "286078512213557452790427043508039360626",
                "241789140306854742961454188452461710875",
                "83441191614807536354689381197301512841",
                "262059835998961676086911433830457575535",
                "301133630298617312456199687547688286995",
                "202085559153190256010867507969852365102",
                "103135069332671213204885403905257683662",
                "42982089545384229737797148334791743045",
                "242863890653840196196030300438076485979",
                "191286845038798908907065235764230815026",
                "103251180635809783272191462470945276027",
                "145925226955266485012272184808482627454",
                "5985586403280676399624459985428720851",
                "235699647439434053363965129957896659818",
                "230020978182409958660444302416723557390",
                "50325927934901271970516351223829453365",
                "271158877314015673402855397346009593868",
                "150671140698853918069250513902903087402",
                "78280349141596891715924072316370580218",
                "302717973380483517858287986196285838838",
                "329305182001377608841970185918840467507",
                "257369295453954457772649606882959932997",
                "113301957106642542394098911236068220558",
                "121712917957453000368177804460479714676",
                "68838777183800431608144784894308796609",
                "300840310654846792023005765068706428558",
                "74984595877538455641216885140514177482",
                "139892350477176823751267183410527009807",
                "280393001903846769411574858331483106241",
                "89857992124729527477499615960622545768"
            ],
            "threshold": 0.9
        },
        "id": "CVE-2026-49854-6b66e329",
        "target": {
            "file": "tornado/speedups.c"
        },
        "source": "https://github.com/tornadoweb/tornado/commit/96dc88c2a05705287856b2cd6b4b4034f9a6aaac",
        "signature_version": "v1"
    },
    {
        "signature_type": "Function",
        "deprecated": false,
        "digest": {
            "length": 804.0,
            "function_hash": "282508762915572268356710576646415704649"
        },
        "id": "CVE-2026-49854-b745e279",
        "target": {
            "function": "websocket_mask",
            "file": "tornado/speedups.c"
        },
        "source": "https://github.com/tornadoweb/tornado/commit/96dc88c2a05705287856b2cd6b4b4034f9a6aaac",
        "signature_version": "v1"
    }
]
source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-49854.json"
vanir_signatures_modified 
"2026-08-12T16:09:42Z"