CVE-2016-3959
The Verify function in crypto/dsa/dsa.go in Go before 1.5.4 and 1.6.x before 1.6.1 does not properly check parameters passed to the big integer library, which might allow remote attackers to cause a denial of service (infinite loop) via a crafted public key to a program that uses HTTPS client certificates or SSH server libraries.
CVSS
- Version: 3.0
- Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- Base score: 7.5
Exploitation probability (EPSS)
- Probability of exploitation in the next 30 days: 4.42%
- Percentile among all scored CVEs: 91
- Score date: 10/7/2026
EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).
💥 Public exploits
Exploit code or detection templates are publicly available. This is not the same as confirmed active exploitation (KEV), but it raises the risk: patch with priority.
- Proof of concept on GitHub (unverified) · List of proofs of concept on GitHub
⚠️ GitHub proofs of concept are not verified: some are fake or contain malware. Never run them outside an isolated lab.
Affected technologies (3)
CWEs
- CWE-20
References
- http://lists.fedoraproject.org/pipermail/package-announce/2016-April/182526.html
- http://lists.fedoraproject.org/pipermail/package-announce/2016-April/183106.html
- http://lists.fedoraproject.org/pipermail/package-announce/2016-April/183137.html
- http://lists.opensuse.org/opensuse-updates/2016-05/msg00077.html
- http://rhn.redhat.com/errata/RHSA-2016-1538.html
- http://www.openwall.com/lists/oss-security/2016/04/05/1
- http://www.openwall.com/lists/oss-security/2016/04/05/2
- https://go-review.googlesource.com/#/c/21533/
- https://groups.google.com/forum/#%21topic/golang-announce/9eqIHqaWvck
- http://lists.fedoraproject.org/pipermail/package-announce/2016-April/182526.html
- http://lists.fedoraproject.org/pipermail/package-announce/2016-April/183106.html
- http://lists.fedoraproject.org/pipermail/package-announce/2016-April/183137.html
- http://lists.opensuse.org/opensuse-updates/2016-05/msg00077.html
- http://rhn.redhat.com/errata/RHSA-2016-1538.html
- http://www.openwall.com/lists/oss-security/2016/04/05/1
- http://www.openwall.com/lists/oss-security/2016/04/05/2
- https://go-review.googlesource.com/#/c/21533/
- https://groups.google.com/forum/#%21topic/golang-announce/9eqIHqaWvck
Raw JSON (NVD)
Show
{
"id": "CVE-2016-3959",
"cveTags": [],
"metrics": {
"cvssMetricV2": [
{
"type": "Primary",
"source": "nvd@nist.gov",
"cvssData": {
"version": "2.0",
"baseScore": 5,
"accessVector": "NETWORK",
"vectorString": "AV:N/AC:L/Au:N/C:N/I:N/A:P",
"authentication": "NONE",
"integrityImpact": "NONE",
"accessComplexity": "LOW",
"availabilityImpact": "PARTIAL",
"confidentialityImpact": "NONE"
},
"acInsufInfo": false,
"impactScore": 2.9,
"baseSeverity": "MEDIUM",
"obtainAllPrivilege": false,
"exploitabilityScore": 10,
"obtainUserPrivilege": false,
"obtainOtherPrivilege": false,
"userInteractionRequired": false
}
],
"cvssMetricV30": [
{
"type": "Primary",
"source": "nvd@nist.gov",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.0",
"baseScore": 7.5,
"attackVector": "NETWORK",
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"integrityImpact": "NONE",
"userInteraction": "NONE",
"attackComplexity": "LOW",
"availabilityImpact": "HIGH",
"privilegesRequired": "NONE",
"confidentialityImpact": "NONE"
},
"impactScore": 3.6,
"exploitabilityScore": 3.9
}
]
},
"affected": [
{
"source": "cve@mitre.org",
"affectedData": [
{
"vendor": "n/a",
"product": "n/a",
"versions": [
{
"status": "affected",
"version": "n/a"
}
]
}
]
}
],
"published": "2016-05-23T19:59:04.477",
"references": [
{
"url": "http://lists.fedoraproject.org/pipermail/package-announce/2016-April/182526.html",
"source": "cve@mitre.org"
},
{
"url": "http://lists.fedoraproject.org/pipermail/package-announce/2016-April/183106.html",
"source": "cve@mitre.org"
},
{
"url": "http://lists.fedoraproject.org/pipermail/package-announce/2016-April/183137.html",
"source": "cve@mitre.org"
},
{
"url": "http://lists.opensuse.org/opensuse-updates/2016-05/msg00077.html",
"source": "cve@mitre.org"
},
{
"url": "http://rhn.redhat.com/errata/RHSA-2016-1538.html",
"source": "cve@mitre.org"
},
{
"url": "http://www.openwall.com/lists/oss-security/2016/04/05/1",
"source": "cve@mitre.org"
},
{
"url": "http://www.openwall.com/lists/oss-security/2016/04/05/2",
"source": "cve@mitre.org"
},
{
"url": "https://go-review.googlesource.com/#/c/21533/",
"source": "cve@mitre.org"
},
{
"url": "https://groups.google.com/forum/#%21topic/golang-announce/9eqIHqaWvck",
"source": "cve@mitre.org"
},
{
"url": "http://lists.fedoraproject.org/pipermail/package-announce/2016-April/182526.html",
"source": "af854a3a-2127-422b-91ae-364da2661108"
},
{
"url": "http://lists.fedoraproject.org/pipermail/package-announce/2016-April/183106.html",
"source": "af854a3a-2127-422b-91ae-364da2661108"
},
{
"url": "http://lists.fedoraproject.org/pipermail/package-announce/2016-April/183137.html",
"source": "af854a3a-2127-422b-91ae-364da2661108"
},
{
"url": "http://lists.opensuse.org/opensuse-updates/2016-05/msg00077.html",
"source": "af854a3a-2127-422b-91ae-364da2661108"
},
{
"url": "http://rhn.redhat.com/errata/RHSA-2016-1538.html",
"source": "af854a3a-2127-422b-91ae-364da2661108"
},
{
"url": "http://www.openwall.com/lists/oss-security/2016/04/05/1",
"source": "af854a3a-2127-422b-91ae-364da2661108"
},
{
"url": "http://www.openwall.com/lists/oss-security/2016/04/05/2",
"source": "af854a3a-2127-422b-91ae-364da2661108"
},
{
"url": "https://go-review.googlesource.com/#/c/21533/",
"source": "af854a3a-2127-422b-91ae-364da2661108"
},
{
"url": "https://groups.google.com/forum/#%21topic/golang-announce/9eqIHqaWvck",
"source": "af854a3a-2127-422b-91ae-364da2661108"
}
],
"vulnStatus": "Modified",
"weaknesses": [
{
"type": "Primary",
"source": "nvd@nist.gov",
"description": [
{
"lang": "en",
"value": "CWE-20"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "The Verify function in crypto/dsa/dsa.go in Go before 1.5.4 and 1.6.x before 1.6.1 does not properly check parameters passed to the big integer library, which might allow remote attackers to cause a denial of service (infinite loop) via a crafted public key to a program that uses HTTPS client certificates or SSH server libraries."
},
{
"lang": "es",
"value": "La función Verify en crypto/dsa/dsa.go en Go en versiones anteriores a 1.5.4 y 1.6.x en versiones anteriores a 1.6.1 no comprueba correctamente los parámetros pasados a la gran librería de entero, lo que podría permitir a atacantes remotos provocar una denegación de servicio (bucle infinito) a través de una clave pública manipulada a un programa que usa certificados de clientes HTTPS o servidores de librerías SSH."
}
],
"lastModified": "2026-06-17T00:46:38.537",
"configurations": [
{
"nodes": [
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:o:opensuse:leap:42.1:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "4863BE36-D16A-4D75-90D9-FD76DB5B48B7"
}
],
"operator": "OR"
}
]
},
{
"nodes": [
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:a:golang:go:1.6:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "5257EB6A-67DC-454A-AC53-CB2466EB8774"
}
],
"operator": "OR"
}
]
},
{
"nodes": [
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:o:fedoraproject:fedora:22:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "253C303A-E577-4488-93E6-68A8DD942C38"
},
{
"criteria": "cpe:2.3:o:fedoraproject:fedora:23:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "E79AB8DD-C907-4038-A931-1A5A4CFB6A5B"
},
{
"criteria": "cpe:2.3:o:fedoraproject:fedora:24:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "C729D5D1-ED95-443A-9F53-5D7C2FD9B80C"
}
],
"operator": "OR"
}
]
},
{
"nodes": [
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:a:golang:go:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "8A030B51-5387-42E6-A885-FE111B4A9BF8",
"versionEndIncluding": "1.5"
}
],
"operator": "OR"
}
]
}
],
"sourceIdentifier": "cve@mitre.org"
}