Microsoft has issued a CVE for a bug in the GitHub Copilot plugin that sits inside JetBrains IDEs. The Injection, summarizing the November 10, 2026 advisory, reports that CVE-2026-83953 is a command-injection flaw that lets a local attacker with low privileges read information. Microsoft scores it 5.5. The fix is plugin version 1.17.0-251.
Quick Take
- Product: GitHub Copilot plugin for JetBrains IDEs.
- Bug: Command injection leading to local information disclosure, published November 10, 2026.
- Score: CVSS 5.5 (Medium in The Injection’s week-46 grouping; still a patch-now item for any machine that runs the plugin).
- Fix: Update the plugin to 1.17.0-251 or later.
What happened
Coding-agent plugins run with the same reach as the editor: they can see the repo, the terminal, and often local files. A command-injection bug in that path does not need to be a remote 9.8 to matter. CVE-2026-83953 is local and requires low privileges, which means another user or process on the same machine, or malware that already has a foothold, could use the Copilot plugin to read data it should not.
Microsoft’s MSRC entry is the canonical record. Public summaries on November 10 did not describe a remote, unauthenticated path and did not report in-the-wild exploitation.
What you should do
- Update the GitHub Copilot plugin in IntelliJ IDEA, PyCharm, WebStorm and any other JetBrains IDE to 1.17.0-251 or later.
- If you cannot update immediately, treat the plugin as a local privilege boundary: do not leave it installed on shared or multi-user workstations until the patch is on.
- This is a different issue from the October Patch Tuesday Copilot bugs in Visual Studio and SQL Server Management Studio, which involved a trailing dot in a filename and MCP configuration. Do not assume one patch covers both families.
What it means
For developers, this is a routine but necessary plugin update. For security teams, it is another data point that AI coding assistants are now in the same patch cadence as the IDE itself. A “local, low-privilege, information disclosure” CVE is easy to deprioritize; on a laptop that holds production secrets in .env files, it is still a real exposure.
About the analysis
Researched and written with AI assistance under the editorial responsibility of the i10X News team. The title image is an AI-generated illustration. Read our AI Use Policy. Spotted an error? Request a correction.
This i10x report is based on Microsoft’s CVE-2026-83953 record as summarized in The Injection’s week-46 roundup (November 9–15, 2026) and the MSRC update-guide URL. i10x did not test the plugin.
