CVE-2026-6276

See a problem?
Please try reporting it to the source first.
Source
https://cve.org/CVERecord?id=CVE-2026-6276
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-6276.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-6276
Aliases
Downstream
Related
Published
2026-05-13T08:28:19.273Z
Modified
2026-07-08T08:12:41.217272564Z
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
stale custom cookie host causes cookie leak
Details

Using libcurl, when a custom Host: header is first set for an HTTP request and a second request is subsequently done using the same easy handle but without the custom Host: header set, the second request would use stale information and pass on cookies meant for the first host in the second request. Leak them.

Database specific 
{
    "unresolved_ranges": [
        {
            "source": "AFFECTED_FIELD",
            "extracted_events": [
                {
                    "introduced": "8.19.0"
                },
                {
                    "last_affected": "8.19.0"
                },
                {
                    "introduced": "8.18.0"
                },
                {
                    "last_affected": "8.18.0"
                },
                {
                    "introduced": "8.17.0"
                },
                {
                    "last_affected": "8.17.0"
                },
                {
                    "introduced": "8.16.0"
                },
                {
                    "last_affected": "8.16.0"
                },
                {
                    "introduced": "8.15.0"
                },
                {
                    "last_affected": "8.15.0"
                },
                {
                    "introduced": "8.14.1"
                },
                {
                    "last_affected": "8.14.1"
                },
                {
                    "introduced": "8.14.0"
                },
                {
                    "last_affected": "8.14.0"
                },
                {
                    "introduced": "8.13.0"
                },
                {
                    "last_affected": "8.13.0"
                },
                {
                    "introduced": "8.12.1"
                },
                {
                    "last_affected": "8.12.1"
                },
                {
                    "introduced": "8.12.0"
                },
                {
                    "last_affected": "8.12.0"
                },
                {
                    "introduced": "8.11.1"
                },
                {
                    "last_affected": "8.11.1"
                },
                {
                    "introduced": "8.11.0"
                },
                {
                    "last_affected": "8.11.0"
                },
                {
                    "introduced": "8.10.1"
                },
                {
                    "last_affected": "8.10.1"
                },
                {
                    "introduced": "8.10.0"
                },
                {
                    "last_affected": "8.10.0"
                },
                {
                    "introduced": "8.9.1"
                },
                {
                    "last_affected": "8.9.1"
                },
                {
                    "introduced": "8.9.0"
                },
                {
                    "last_affected": "8.9.0"
                },
                {
                    "introduced": "8.8.0"
                },
                {
                    "last_affected": "8.8.0"
                },
                {
                    "introduced": "8.7.1"
                },
                {
                    "last_affected": "8.7.1"
                },
                {
                    "introduced": "8.7.0"
                },
                {
                    "last_affected": "8.7.0"
                },
                {
                    "introduced": "8.6.0"
                },
                {
                    "last_affected": "8.6.0"
                },
                {
                    "introduced": "8.5.0"
                },
                {
                    "last_affected": "8.5.0"
                },
                {
                    "introduced": "8.4.0"
                },
                {
                    "last_affected": "8.4.0"
                },
                {
                    "introduced": "8.3.0"
                },
                {
                    "last_affected": "8.3.0"
                },
                {
                    "introduced": "8.2.1"
                },
                {
                    "last_affected": "8.2.1"
                },
                {
                    "introduced": "8.2.0"
                },
                {
                    "last_affected": "8.2.0"
                },
                {
                    "introduced": "8.1.2"
                },
                {
                    "last_affected": "8.1.2"
                },
                {
                    "introduced": "8.1.1"
                },
                {
                    "last_affected": "8.1.1"
                },
                {
                    "introduced": "8.1.0"
                },
                {
                    "last_affected": "8.1.0"
                },
                {
                    "introduced": "8.0.1"
                },
                {
                    "last_affected": "8.0.1"
                },
                {
                    "introduced": "8.0.0"
                },
                {
                    "last_affected": "8.0.0"
                },
                {
                    "introduced": "7.88.1"
                },
                {
                    "last_affected": "7.88.1"
                },
                {
                    "introduced": "7.88.0"
                },
                {
                    "last_affected": "7.88.0"
                },
                {
                    "introduced": "7.87.0"
                },
                {
                    "last_affected": "7.87.0"
                },
                {
                    "introduced": "7.86.0"
                },
                {
                    "last_affected": "7.86.0"
                },
                {
                    "introduced": "7.85.0"
                },
                {
                    "last_affected": "7.85.0"
                },
                {
                    "introduced": "7.84.0"
                },
                {
                    "last_affected": "7.84.0"
                },
                {
                    "introduced": "7.83.1"
                },
                {
                    "last_affected": "7.83.1"
                },
                {
                    "introduced": "7.83.0"
                },
                {
                    "last_affected": "7.83.0"
                },
                {
                    "introduced": "7.82.0"
                },
                {
                    "last_affected": "7.82.0"
                },
                {
                    "introduced": "7.81.0"
                },
                {
                    "last_affected": "7.81.0"
                },
                {
                    "introduced": "7.80.0"
                },
                {
                    "last_affected": "7.80.0"
                },
                {
                    "introduced": "7.79.1"
                },
                {
                    "last_affected": "7.79.1"
                },
                {
                    "introduced": "7.79.0"
                },
                {
                    "last_affected": "7.79.0"
                },
                {
                    "introduced": "7.78.0"
                },
                {
                    "last_affected": "7.78.0"
                },
                {
                    "introduced": "7.77.0"
                },
                {
                    "last_affected": "7.77.0"
                },
                {
                    "introduced": "7.76.1"
                },
                {
                    "last_affected": "7.76.1"
                },
                {
                    "introduced": "7.76.0"
                },
                {
                    "last_affected": "7.76.0"
                },
                {
                    "introduced": "7.75.0"
                },
                {
                    "last_affected": "7.75.0"
                },
                {
                    "introduced": "7.74.0"
                },
                {
                    "last_affected": "7.74.0"
                },
                {
                    "introduced": "7.73.0"
                },
                {
                    "last_affected": "7.73.0"
                },
                {
                    "introduced": "7.72.0"
                },
                {
                    "last_affected": "7.72.0"
                },
                {
                    "introduced": "7.71.1"
                },
                {
                    "last_affected": "7.71.1"
                },
                {
                    "introduced": "7.71.0"
                },
                {
                    "last_affected": "7.71.0"
                }
            ]
        }
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/6xxx/CVE-2026-6276.json",
    "cna_assigner": "curl"
}
References

Affected packages

Git / github.com/curl/curl

Affected ranges

Type
GIT
Repo
https://github.com/curl/curl
Events
Introduced
e9db32a09af03f27e86d1251a9e68e9b7486d371
Fixed
a05f34973e6c4bb629d018f7cb51487be1c904d8
Database specific 
{
    "source": "CPE_RANGE",
    "cpe": "cpe:2.3:a:haxx:curl:*:*:*:*:*:*:*:*",
    "extracted_events": [
        {
            "introduced": "7.71.0"
        },
        {
            "fixed": "8.20.0"
        }
    ]
}

Affected versions

Other
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_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

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-6276.json"