Microsoft Security Advisory CVE-2026-102870 - ASP.NET Core Remote Code Execution Vulnerability

Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

Severity and exploitation

• CISA KEV Not listed.
• EPSS 0.0091, the 59th percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

1. 13 Oct 2026, 19:01 UTC Confirmed by the CVE List
2. 13 Oct 2026, 20:27 UTC Confirmed by GitHub Advisory Database
3. 31 Oct 2026, 15:21 UTC First seen by agentprime
4. 31 Oct 2026, 15:21 UTC Confirmed by OSV

Sources

• GitHub Advisory Database: GHSA-g27p-qf6j-c96c
• OSV: GHSA-g27p-qf6j-c96c
• github.com/dotnet/aspnetcore/security/advisories/GHSA-g27p-qf6j-c96c
• nvd.nist.gov/vuln/detail/CVE-2026-102870
• github.com/dotnet/announcements/issues/445
• github.com/dotnet/announcements/issues/492
• github.com/dotnet/aspnetcore
• github.com/dotnet/aspnetcore/discussions/69791
• github.com/dotnet/aspnetcore/discussions/70039
• msrc.microsoft.com/update-guide/vulnerability/CVE-2026-102870

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.