cve-2026-8458
MEDIUM CVSS 6.5 nvd
Description
libcurl might in some circumstances reuse the wrong connection when asked to do Negotiate-authenticated ones, even when they are set to use different "services". libcurl features a pool of recent connections so that subsequent requests can reuse an existing connection to avoid overhead. When reusing a connection a range of criteria must be met. Due to a logical error in the code, a request that was issued by an application could wrongfully reuse an existing connection to the same server that was authenticated using different services.
Timeline
- Published
- 2026-07-03
- Last Modified
- 2026-09-15
CVSS Details
- Attack Vector
- NETWORK
- Attack Complexity
- LOW
- Privileges Required
- LOW
Affected Products
- haxx curl
Weaknesses (CWE)
CVSS metrics
| Version | Base | Severity | Vector | Exploitability | Impact | Source |
|---|---|---|---|---|---|---|
| 3.1 | 6.5 | MEDIUM | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N |
2.8 | 3.6 | 134c704f-9b21-4f2e-91b3-4a467353bcc0 |
CPE configurations
OR
| CPE | Version range | Vulnerable |
|---|---|---|
cpe:2.3:a:haxx:curl:*:*:*:*:*:*:*:* |
>= 7.46.0, < 8.20.0 | yes |
NVD metadata
- NVD status
- Modified
- Source identifier
2499f714-1537-4658-8207-48ae4bb9eae9
References
- https://curl.se/docs/CVE-2026-8458.html Patch, Vendor Advisory
- https://curl.se/docs/CVE-2026-8458.json Vendor Advisory
- https://hackerone.com/reports/3721183 Exploit, Issue Tracking, Third Party Advisory
Linked Vulnerabilities
{
"cvss": 6.5,
"datePublished": "2026-07-03T07:16:24.630",
"dateUpdated": "2026-09-15T07:16:32.327",
"description": "libcurl might in some circumstances reuse the wrong connection when asked to\ndo Negotiate-authenticated ones, even when they are set to use different\n\"services\".\n\nlibcurl features a pool of recent connections so that subsequent requests can\nreuse an existing connection to avoid overhead.\n\nWhen reusing a connection a range of criteria must be met. Due to a logical\nerror in the code, a request that was issued by an application could\nwrongfully reuse an existing connection to the same server that was\nauthenticated using different services.",
"id": "CVE-2026-8458",
"raw": {
"affected": [
{
"affectedData": [
{
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"product": "curl",
"vendor": "curl",
"versions": [
{
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"status": "affected",
"version": "7.43.0",
"versionType": "semver"
},
{
"lessThan": "8.16.1",
"status": "affected",
"version": "8.15.0",
"versionType": "semver"
},
{
"lessThan": "8.20.1",
"status": "affected",
"version": "8.17.0",
"versionType": "semver"
}
]
},
{
"defaultStatus": "unaffected",
"product": "curl",
"repo": "https://github.com/curl/curl.git",
"vendor": "curl",
"versions": [
{
"lessThan": "5e99b73cf441d9c369768b9cd48b5389b9a2503d",
"status": "affected",
"version": "97c272e5d173ad5f706443e2477f0a84f0044edd",
"versionType": "git"
}
]
},
{
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{
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{
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{
"status": "affected",
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},
{
"status": "affected",
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},
{
"status": "affected",
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{
"status": "affected",
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{
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{
"status": "affected",
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{
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{
"status": "affected",
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},
{
"status": "affected",
"version": "8.12.0"
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{
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},
{
"status": "affected",
"version": "8.11.0"
},
{
"status": "affected",
"version": "8.10.1"
},
{
"status": "affected",
"version": "8.10.0"
},
{
"status": "affected",
"version": "8.9.1"
},
{
"status": "affected",
"version": "8.9.0"
},
{
"status": "affected",
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},
{
"status": "affected",
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{
"status": "affected",
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{
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{
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{
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{
"status": "affected",
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{
"status": "affected",
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{
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{
"status": "affected",
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{
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{
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{
"status": "affected",
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{
"status": "affected",
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},
{
"status": "affected",
"version": "7.88.1"
},
{
"status": "affected",
"version": "7.88.0"
},
{
"status": "affected",
"version": "7.87.0"
},
{
"status": "affected",
"version": "7.86.0"
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{
"status": "affected",
"version": "7.85.0"
},
{
"status": "affected",
"version": "7.84.0"
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{
"status": "affected",
"version": "7.83.1"
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{
"status": "affected",
"version": "7.83.0"
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{
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{
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{
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{
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{
"status": "affected",
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{
"status": "affected",
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{
"status": "affected",
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{
"status": "affected",
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{
"status": "affected",
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{
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{
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{
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{
"status": "affected",
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{
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},
{
"status": "affected",
"version": "7.71.0"
},
{
"status": "affected",
"version": "7.70.0"
},
{
"status": "affected",
"version": "7.69.1"
},
{
"status": "affected",
"version": "7.69.0"
},
{
"status": "affected",
"version": "7.68.0"
},
{
"status": "affected",
"version": "7.67.0"
},
{
"status": "affected",
"version": "7.66.0"
},
{
"status": "affected",
"version": "7.65.3"
},
{
"status": "affected",
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},
{
"status": "affected",
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},
{
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{
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},
{
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{
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{
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{
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{
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{
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{
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{
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{
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{
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{
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{
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{
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{
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{
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{
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{
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{
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{
"status": "affected",
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{
"status": "affected",
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{
"status": "affected",
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{
"status": "affected",
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{
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{
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{
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{
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"version": "7.47.1"
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{
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{
"status": "affected",
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},
{
"status": "affected",
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},
{
"status": "affected",
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{
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}
]
}
],
"source": "2499f714-1537-4658-8207-48ae4bb9eae9"
}
],
"configurations": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:a:haxx:curl:*:*:*:*:*:*:*:*",
"matchCriteriaId": "20E8DD93-DCA1-4855-A693-6C79DC27D359",
"versionEndExcluding": "8.20.0",
"versionStartIncluding": "7.46.0",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "libcurl might in some circumstances reuse the wrong connection when asked to\ndo Negotiate-authenticated ones, even when they are set to use different\n\"services\".\n\nlibcurl features a pool of recent connections so that subsequent requests can\nreuse an existing connection to avoid overhead.\n\nWhen reusing a connection a range of criteria must be met. Due to a logical\nerror in the code, a request that was issued by an application could\nwrongfully reuse an existing connection to the same server that was\nauthenticated using different services."
}
],
"id": "CVE-2026-8458",
"lastModified": "2026-09-15T07:16:32.327",
"metrics": {
"cvssMetricV31": [
{
"cvssData": {
"attackComplexity": "LOW",
"attackVector": "NETWORK",
"availabilityImpact": "NONE",
"baseScore": 6.5,
"baseSeverity": "MEDIUM",
"confidentialityImpact": "NONE",
"integrityImpact": "HIGH",
"privilegesRequired": "LOW",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N",
"version": "3.1"
},
"exploitabilityScore": 2.8,
"impactScore": 3.6,
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"type": "Secondary"
}
],
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{
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"options": [
{
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{
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},
{
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}
],
"role": "CISA Coordinator",
"timestamp": "2026-07-06T17:31:14.007899Z",
"version": "2.0.3"
}
}
]
},
"published": "2026-07-03T07:16:24.630",
"references": [
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],
"sourceIdentifier": "2499f714-1537-4658-8207-48ae4bb9eae9",
"vulnStatus": "Modified",
"weaknesses": [
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{
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"value": "CWE-488"
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"source": "2499f714-1537-4658-8207-48ae4bb9eae9",
"type": "Secondary"
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{
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"source": "nvd@nist.gov",
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]
},
"severity": "MEDIUM",
"source": "nvd",
"title": "libcurl might in some circumstances reuse the wrong connection when asked to\ndo Negotiate-authenticated ones, even wh..."
}
Enrichment data
Aggregated bundle (all enrichments)