# Microsoft QUIC: Remote Code Execution Vulnerability

Advisory record · `GHSA-92f5-vc22-8j33`

- **Identifiers:** `GHSA-92f5-vc22-8j33` · `CVE-2026-62815`
- **State:** Confirmed
- **Severity:** CVSS 9.8 Critical
- **Critical:** Yes: CVSS 9+
- **Weakness (CWE):** [CWE-416](https://cwe.mitre.org/data/definitions/416.html)
- **Tags:** [Memory corruption](https://agentprime.io/advisories/tag/memory-corruption.md)
- **Published:** 8 Sept 2026
- **Updated:** 8 Sept 2026
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 8 Sept 2026, 20:27 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Critical

Critical, because:

- CVSS score 9.8: 9.0 or more.

How we decide what’s critical: <https://agentprime.io/advisories/critical.md>

## Affected packages

- `Microsoft.Native.Quic.MsQuic.OpenSSL` (NuGet): affected `>=2.5.3, <2.5.10 || <2.4.19`; fixed in `2.5.10`, `2.4.19`
- `Microsoft.Native.Quic.MsQuic.Schannel` (NuGet): affected `>=2.5.3, <2.5.10 || <2.4.19`; fixed in `2.5.10`, `2.4.19`

## 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

- 9.8 Critical, CVSS 3.1: `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C`, from CNA (microsoft)

- **CISA KEV:** Not listed.
- **EPSS:** 0.0097, the 62nd percentile, on 8 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

- 31 Oct 2026, 15:21 UTC: First seen by agentprime
- 31 Oct 2026, 15:21 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-92f5-vc22-8j33)

## Sources

- [GitHub Advisory Database: GHSA-92f5-vc22-8j33](https://github.com/advisories/GHSA-92f5-vc22-8j33)
- [OSV: GHSA-92f5-vc22-8j33](https://osv.dev/vulnerability/GHSA-92f5-vc22-8j33)
- <https://github.com/microsoft/msquic/security/advisories/GHSA-92f5-vc22-8j33>
- <https://nvd.nist.gov/vuln/detail/CVE-2026-62815>
- <https://github.com/microsoft/msquic/pull/6217>
- <https://github.com/microsoft/msquic/pull/6219>
- <https://github.com/microsoft/msquic/pull/6220>
- <https://github.com/microsoft/msquic/commit/583e7d5b509bb0bfa3518482d98879b6eda41ad0>
- <https://github.com/microsoft/msquic/commit/9ff06b71fd4b4d5258361598ada5b24cbc1beb20>
- <https://github.com/microsoft/msquic/commit/e0f55b5fdc9fff0b4465976d066ebd22fb7e2b3b>
- <https://github.com/microsoft/msquic>
- <https://github.com/microsoft/msquic/releases/tag/v2.4.19>
- <https://github.com/microsoft/msquic/releases/tag/v2.5.10>
- <https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-62815>

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.

## Check whether this affects you

A Match means an installed version is in the affected range above. Most don’t affect the app; agentprime hasn’t analysed this one yet.

- With the agentprime MCP server (<https://api.agentprime.io/mcp>), ask your agent to check the project: `check_lockfile` sends a lockfile, `check_packages` a list of installed packages, and both return the Matches and the upgrades that clear them. `get_advisory` returns this record. Setup: <https://agentprime.io/mcp.md>
- In a browser: <https://agentprime.io/check/> reads your lockfile in the browser, never uploading it.
- Whether it touches your code, with file and line: the Claude Code plugin, <https://agentprime.io/plugin.md>
- As JSON: <https://api.agentprime.io/v1/advisories/GHSA-92f5-vc22-8j33>, or `POST https://api.agentprime.io/v1/match` with your packages (<https://agentprime.io/api.md>)

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The web page: <https://agentprime.io/advisories/GHSA-92f5-vc22-8j33/>. Everything for agents: <https://agentprime.io/llms.txt>.