CURL-CVE-2026-12064

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Source
https://curl.se/docs/CVE-2026-12064.html
Import Source
https://curl.se/docs/CURL-CVE-2026-12064.json
JSON Data
https://api.osv.dev/v1/vulns/CURL-CVE-2026-12064
Aliases
  • CVE-2026-12064
Published
2026-06-24T08:00:00Z
Modified
2026-06-24T08:07:07.622902Z
Summary
proto-default skips SSH verification
Details

When a user invokes curl using a schemeless URL combined with --proto-default sftp (or scp), a disconnect occurs between the tool layer and libcurl. The tool layer incorrectly infers the URL scheme, which erroneously bypasses the initialization of critical SSH security options like CURLOPTSSHHOSTPUBLICKEYSHA256 and CURLOPTSSHKNOWNHOSTS. Conversely, the libcurl runtime successfully honors CURLOPTDEFAULT_PROTOCOL and establishes the connection via SFTP/SCP as specified. Because the tool layer skipped the security configuration, these SSH host verification options are silently omitted, causing curl to connect to an unverified SSH remote host without throwing an error.

Database specific 
{
    "package": "curl",
    "URL": "https://curl.se/docs/CVE-2026-12064.json",
    "last_affected": "8.20.0",
    "issue": "https://hackerone.com/reports/3797526",
    "affects": "tool",
    "severity": "Low",
    "www": "https://curl.se/docs/CVE-2026-12064.html",
    "CWE": {
        "desc": "Improper Validation of Certificate with Host Mismatch",
        "id": "CWE-297"
    }
}
References
Credits
    • alienowo on hackerone (AntAISecurityLab) - FINDER
    • Daniel Stenberg - REMEDIATION_DEVELOPER

Affected packages

Git / github.com/curl/curl.git

Affected ranges

Type
SEMVER
Events
Introduced
7.81.0
Fixed
8.21.0
Type
GIT
Repo
https://github.com/curl/curl.git
Events
Introduced
18270893abdb19f0ca170c118f8a2847dbd304be
Fixed
ab3bb8cd8be8f9d4acb97da0418abc279182041e

Affected versions

7.*
7.81.0
7.82.0
7.83.0
7.83.1
7.84.0
7.85.0
7.86.0
7.87.0
7.88.0
7.88.1
8.*
8.0.0
8.0.1
8.1.0
8.1.1
8.1.2
8.10.0
8.10.1
8.11.0
8.11.1
8.12.0
8.12.1
8.13.0
8.14.0
8.14.1
8.15.0
8.16.0
8.17.0
8.18.0
8.19.0
8.2.0
8.2.1
8.20.0
8.3.0
8.4.0
8.5.0
8.6.0
8.7.0
8.7.1
8.8.0
8.9.0
8.9.1
Other
curl-7_81_0
curl-7_82_0
curl-7_83_0
curl-7_83_1
curl-7_84_0
curl-7_85_0
curl-7_86_0
curl-7_87_0
curl-7_88_0
curl-7_88_1
curl-8_0_0
curl-8_0_1
curl-8_10_0
curl-8_10_1
curl-8_11_0
curl-8_11_1
curl-8_12_0
curl-8_12_1
curl-8_13_0
curl-8_14_0
curl-8_14_1
curl-8_15_0
curl-8_16_0
curl-8_17_0
curl-8_18_0
curl-8_19_0
curl-8_1_0
curl-8_1_1
curl-8_1_2
curl-8_20_0
curl-8_2_0
curl-8_2_1
curl-8_3_0
curl-8_4_0
curl-8_5_0
curl-8_6_0
curl-8_7_0
curl-8_7_1
curl-8_8_0
curl-8_9_0
curl-8_9_1
rc-8_18_0-1
rc-8_18_0-2
rc-8_18_0-3
rc-8_19_0-1
rc-8_19_0-2
rc-8_19_0-3
rc-8_20_0-1
rc-8_20_0-2
rc-8_20_0-3
rc-8_21_0-1
rc-8_21_0-2
tiny-curl-8_4_0

Database specific

source 
"https://curl.se/docs/CURL-CVE-2026-12064.json"
vanir_signatures_modified 
"2026-06-24T08:07:07Z"
vanir_signatures 
[
    {
        "target": {
            "file": "src/config2setopts.c",
            "function": "url_proto_and_rewrite"
        },
        "id": "CURL-CVE-2026-12064-b3eb1e8d",
        "source": "https://github.com/curl/curl.git/commit/ab3bb8cd8be8f9d4acb97da0418abc279182041e",
        "signature_type": "Function",
        "deprecated": false,
        "digest": {
            "length": 1136.0,
            "function_hash": "93882114240828177653085948016490702110"
        },
        "signature_version": "v1"
    },
    {
        "target": {
            "file": "src/config2setopts.c"
        },
        "id": "CURL-CVE-2026-12064-d5619c82",
        "source": "https://github.com/curl/curl.git/commit/ab3bb8cd8be8f9d4acb97da0418abc279182041e",
        "signature_type": "Line",
        "deprecated": false,
        "digest": {
            "threshold": 0.9,
            "line_hashes": [
                "140522849194369262228739833591374391075",
                "47558339863403131453033268292745221021",
                "15975670465097192282932354355781322912",
                "220902106392793621708295317072227537429",
                "198975573407202876764184453290488326371",
                "3746734021152446245522935287251443430",
                "170664250380509585141008070840604764918",
                "161765996811876613295849122885315630101",
                "5374207038386086385366965339124772674",
                "261071834960052502162471400348777792193",
                "315214669734780166251393141450779423952",
                "11348971201187702211989874254882715935",
                "304598240625625498609896974683940486911",
                "176332074864481965282682475802544330239",
                "61413842227513765548216582872062936189",
                "152095212190975018695576316498032629201",
                "12824638474895083873042971640073707981",
                "147131897269297204095220721174340290043",
                "201687314332511709623400018059706721695",
                "304787371272254069598680308305763126609",
                "293436386607034365026241199574672026404",
                "169057705388842471260387887033403810014",
                "136995815859804498330318491255401917183",
                "48843095567586818894551844502984755450",
                "119204995110705058858166647734024530825"
            ]
        },
        "signature_version": "v1"
    }
]