FKIE_CVE-2026-66303
Vulnerability from fkie_nvd - Published: 2026-09-08 19:18 - Updated: 2026-09-16 19:23
Severity
Summary
Null pointer dereference in Skype for Business allows an authorized attacker to deny service over a network.
References
| URL | Tags | ||
|---|---|---|---|
| secure@microsoft.com | https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-66303 | Patch, Vendor Advisory |
Impacted products
| Vendor | Product | Version | |
|---|---|---|---|
| microsoft | skype_for_business_server | 2015 | |
| microsoft | skype_for_business_server | 2015 | |
| microsoft | skype_for_business_server | 2019 | |
| microsoft | skype_for_business_server | 2019 | |
| microsoft | skype_for_business_server | 2019 | |
| microsoft | skype_for_business_server_subscription_edition | 7.0.2046.849 |
{
"affected": [
{
"affectedData": [
{
"platforms": [
"x64-based Systems"
],
"product": "Skype for Business Server 2015 CU13",
"vendor": "Microsoft",
"versions": [
{
"lessThan": "6.0.9319.885",
"status": "affected",
"version": "9319.0",
"versionType": "custom"
}
]
},
{
"platforms": [
"x64-based Systems"
],
"product": "Skype for Business Server 2019 CU8",
"vendor": "Microsoft",
"versions": [
{
"lessThan": "7.0.2046.569",
"status": "affected",
"version": "2046.0",
"versionType": "custom"
}
]
},
{
"platforms": [
"x64-based Systems"
],
"product": "Skype for Business Server Subscription Edition CU1",
"vendor": "Microsoft",
"versions": [
{
"lessThan": "7.0.2046.879",
"status": "affected",
"version": "2046.0",
"versionType": "custom"
}
]
}
],
"source": "secure@microsoft.com"
}
],
"configurations": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:a:microsoft:skype_for_business_server:2015:cumulative_update_13:*:*:*:*:*:*",
"matchCriteriaId": "590D1547-C998-4BDD-BE06-379099E2D9C7",
"vulnerable": true
},
{
"criteria": "cpe:2.3:a:microsoft:skype_for_business_server:2015:cumulative_update_13_hotfix_2:*:*:*:*:*:*",
"matchCriteriaId": "D7B2DE75-E220-447A-90F6-D077E611945B",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
},
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:a:microsoft:skype_for_business_server:2019:cumulative_update_8:*:*:*:*:*:*",
"matchCriteriaId": "85821F4F-AC9B-4D9E-84A4-A57D842B0D5E",
"vulnerable": true
},
{
"criteria": "cpe:2.3:a:microsoft:skype_for_business_server:2019:cumulative_update_8_hotfix1:*:*:*:*:*:*",
"matchCriteriaId": "8545EA2E-796F-4458-B996-5B907E7927EF",
"vulnerable": true
},
{
"criteria": "cpe:2.3:a:microsoft:skype_for_business_server:2019:cumulative_update_8_hotfix2:*:*:*:*:*:*",
"matchCriteriaId": "96E5BC34-2C62-4F15-AA4F-765F596C7445",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
},
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:a:microsoft:skype_for_business_server_subscription_edition:7.0.2046.849:*:*:*:*:*:*:*",
"matchCriteriaId": "15BD78C6-A65A-4CD6-A91F-CA2876AD848C",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "Null pointer dereference in Skype for Business allows an authorized attacker to deny service over a network."
}
],
"id": "CVE-2026-66303",
"lastModified": "2026-09-16T19:23:02.977",
"metrics": {
"cvssMetricV31": [
{
"cvssData": {
"attackComplexity": "LOW",
"attackVector": "NETWORK",
"availabilityImpact": "HIGH",
"baseScore": 6.5,
"baseSeverity": "MEDIUM",
"confidentialityImpact": "NONE",
"integrityImpact": "NONE",
"privilegesRequired": "LOW",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
"version": "3.1"
},
"exploitabilityScore": 2.8,
"impactScore": 3.6,
"source": "secure@microsoft.com",
"type": "Secondary"
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2026-66303",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-09-08T20:38:45.923349Z",
"version": "2.0.3"
}
}
]
},
"published": "2026-09-08T19:18:07.820",
"references": [
{
"source": "secure@microsoft.com",
"tags": [
"Patch",
"Vendor Advisory"
],
"url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-66303"
}
],
"sourceIdentifier": "secure@microsoft.com",
"vulnStatus": "Analyzed",
"weaknesses": [
{
"description": [
{
"lang": "en",
"value": "CWE-476"
}
],
"source": "secure@microsoft.com",
"type": "Secondary"
}
]
}
Loading…
Loading…
Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
Loading…
The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
Loading…
Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.
Loading…