Vulnerability · CVE-2026-26127
Out-of-bounds read in .NET allows an unauthorized attacker to deny service over a network.
Published Mar 10, 2026 · catalog updated Jun 17, 2026 · Microsoft
Patch now
CVE-2026-26127 is in the CISA known-exploited catalog. Confirm Microsoft against the vendor advisory and apply that fix. The CVSS score does not change the priority.
Gaps on this record
- No version range is stored. A customer cannot check an installed version against this record.
- Severity
- High7.5
- Known exploitation
- CISA KEV and VulnCheck KEV
- EPSS
- 1.22%
- Remediation
- Remediation guidance
- Affected products
- cpe microsoft/.net · cpe microsoft/bcl.memory · vendor Microsoft .net
Out-of-bounds read in .NET allows an unauthorized attacker to deny service over a network.
Are you affected?
Enter the version you run. The result uses only the ranges stored on this record.
The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.
- cpe microsoft/.netversion unspecified
- cpe microsoft/bcl.memoryversion unspecified
- vendor Microsoft .netversion unspecified
How to fix CVE-2026-26127
Recommended remediation
Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.
Official advisories
What to do
Three questions, each answered from this record only. Confirm the vendor advisory before you patch.
Should you patch?
CVE-2026-26127 is in the CISA known-exploited catalog. Confirm Microsoft against the vendor advisory and apply that fix. The CVSS score does not change the priority.
Which versions are affected?
Affected version ranges are not on this record. Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.
What should an analyst verify?
CWE-125: Out-of-bounds Read. EPSS 1.22%. The CISA KEV listing is the exploitation evidence. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.
Code
The project this record applies to. Exploit listings stay in References.
No public source repository is identified for this product.
Timeline
Detection, updates, and resolution for this record.
Mar 10, 2026 · NIST NVD
Detected
Out-of-bounds read in .NET allows an unauthorized attacker to deny service over a network.
Apr 13, 2026 · CISA KEV
Known exploited
Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.
Jun 17, 2026 · NIST NVD
Updated
Out-of-bounds read in .NET allows an unauthorized attacker to deny service over a network.
Sources
- CVE.orgVulnerability recordCVE-2026-26127
Official CVE identifier
cve.org - FIRST EPSSExploitation probabilityCVE-2026-26127
30-day exploitation probability 1.2%
first.org - NIST NVDVulnerability recordCVE-2026-26127
Out-of-bounds read in .NET allows an unauthorized attacker to deny service over a network.
nvd.nist.gov - VulnCheck KEVConfirmed exploitationCVE-2026-26127
Out-of-bounds read in .NET allows an unauthorized attacker to deny service over a network.
vulncheck.com
References
Freshness
Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.