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CVE-2026-62886 Microsoft CVE debrief

CVE-2026-62886 is an integer overflow or wraparound vulnerability in .NET that allows local privilege escalation. The vulnerability affects multiple .NET versions, including .NET 8.0.0 to 8.0.30, 9.0.0 to 9.0.19, and 10.0.0 to 10.0.11, and has a CVSS score of 7.8, indicating high severity. Microsoft has released patches for this vulnerability, which should be applied immediately. System administrators and developers using affected versions should assess exposure and apply patches to prevent potential attacks. Verification of .NET versions and patch levels is necessary to ensure system security. The vulnerability can be exploited by an unauthorized attacker to elevate privileges, A

Vendor
Microsoft
Product
.NET 10.0
CVSS
HIGH 7.8
CISA KEV
Not listed in stored evidence
Original CVE published
2026-08-11
Original CVE updated
2026-09-08
Advisory published
2026-08-11
Advisory updated
2026-09-08

Who should care

System administrators and developers using affected .NET versions should assess exposure and apply patches. This vulnerability requires attention from those responsible for maintaining .NET applications, especially in environments where privilege escalation could have significant impacts.

Why it matters

CVE-2026-62886 is a high-severity vulnerability in .NET that allows local privilege escalation. Affected versions include .NET 8.0.0 to 8.0.30, 9.0.0 to 9.0.19, and 10.0.0 to 10.0.11. Microsoft has released patches, which should be applied immediately. System administrators and developers using affected versions should assess exposure and apply patches to prevent potential attacks.

  • Local privilege escalation is possible, allowing attackers to gain higher-level access.
  • Affected systems may be vulnerable to targeted attacks if not patched.
  • Verification of .NET versions and patch levels is necessary to ensure system security.
  • Remediation priority is high due to the potential for significant impact.

Technical summary

The vulnerability is caused by an integer overflow or wraparound in .NET, which can be exploited by an unauthorized attacker to elevate privileges locally. The CVSS score for this vulnerability is 7.8, indicating a high severity level. Affected .NET versions include 8.0.0 to 8.0.30, 9.0.0 to 9.0.19, and 10.0.0 to 10.0.11. Microsoft has released patches for this vulnerability, which should be applied immediately.

Defensive priority

Apply patches immediately for affected .NET versions, especially for systems with high privilege escalation risk.

Recommended defensive actions

  • Apply patches for affected .NET versions
  • Review and update .NET versions to ensure they are within supported ranges
  • Monitor systems for potential privilege escalation attempts

Evidence notes

The vulnerability is described as an integer overflow or wraparound in .NET, allowing unauthorized attackers to elevate privileges locally. Affected versions include .NET 8.0.0 to 8.0.30, .NET 9.0.0 to 9.0.19, and .NET 10.0.0 to 10.0.11. Microsoft has provided a patch for this vulnerability.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-62886 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-62886

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-62886 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-62886

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.