CURL-CVE-2026-9547

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Source
https://curl.se/docs/CVE-2026-9547.html
Import Source
https://curl.se/docs/CURL-CVE-2026-9547.json
JSON Data
https://api.test.osv.dev/v1/vulns/CURL-CVE-2026-9547
Aliases
Published
2026-06-24T08:00:00Z
Modified
2026-07-07T18:35:03.413955Z
Summary
SSH improper host validation
Details

When a libcurl-based application performs transfers via SCP:// or SFTP:// and utilizes the CURLOPT_SSH_KEYFUNCTION callback, it may silently accept an untrusted server. This vulnerability occurs when a server presents a host key type that does not match the specific key type already recorded for that host in the known_hosts file. Instead of rejecting the mismatch, the callback mechanism fails to properly enforce the restriction, allowing the connection to succeed without warning and risking a potential man-in-the-middle attack.

Database specific 
{
    "package": "curl",
    "affects": "lib",
    "last_affected": "8.20.0",
    "CWE": {
        "id": "CWE-297",
        "desc": "Improper Validation of Certificate with Host Mismatch"
    },
    "issue": "https://hackerone.com/reports/3751712",
    "severity": "Low",
    "www": "https://curl.se/docs/CVE-2026-9547.html",
    "URL": "https://curl.se/docs/CVE-2026-9547.json"
}
References
Credits
    • Joshua Rogers (Aisle Research) - FINDER
    • Joshua Rogers (Aisle Research) - REMEDIATION_DEVELOPER

Affected packages

Git / github.com/curl/curl.git

Affected ranges

Type
SEMVER
Events
Introduced
7.69.0
Fixed
8.21.0
Type
GIT
Repo
https://github.com/curl/curl.git
Events
Introduced
507cf6a13db0375eadd4655b4c64710db29e9cf2
Fixed
0b8dbbc63c98777e4584cb9fbd71df3464008ad1

Affected versions

7.*
7.69.0
7.69.1
7.70.0
7.71.0
7.71.1
7.72.0
7.73.0
7.74.0
7.75.0
7.76.0
7.76.1
7.77.0
7.78.0
7.79.0
7.79.1
7.80.0
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_69_0
curl-7_69_1
curl-7_70_0
curl-7_71_0
curl-7_71_1
curl-7_72_0
curl-7_73_0
curl-7_74_0
curl-7_75_0
curl-7_76_0
curl-7_76_1
curl-7_77_0
curl-7_78_0
curl-7_79_0
curl-7_79_1
curl-7_80_0
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
tiny-curl-7_72_0
tiny-curl-8_4_0

Database specific

vanir_signatures 
[
    {
        "id": "CURL-CVE-2026-9547-e5ddacc0",
        "digest": {
            "length": 4615.0,
            "function_hash": "171591672620915120098914005398439744356"
        },
        "target": {
            "function": "myssh_is_known",
            "file": "lib/vssh/libssh.c"
        },
        "signature_version": "v1",
        "source": "https://github.com/curl/curl.git/commit/0b8dbbc63c98777e4584cb9fbd71df3464008ad1",
        "deprecated": false,
        "signature_type": "Function"
    },
    {
        "id": "CURL-CVE-2026-9547-ffd5c5b3",
        "digest": {
            "line_hashes": [
                "19522727956082994505377891717732253881",
                "17505745399782688697084999810884215111",
                "65466782891270922555303879365870593631",
                "39998244195617753293703183793609467932"
            ],
            "threshold": 0.9
        },
        "target": {
            "file": "lib/vssh/libssh.c"
        },
        "signature_version": "v1",
        "source": "https://github.com/curl/curl.git/commit/0b8dbbc63c98777e4584cb9fbd71df3464008ad1",
        "deprecated": false,
        "signature_type": "Line"
    }
]
source 
"https://curl.se/docs/CURL-CVE-2026-9547.json"
vanir_signatures_modified 
"2026-07-07T18:35:03Z"