GitHub Copilot for JetBrains: a command injection leaks local data
CVE-2026-83953 is a command injection flaw in the GitHub Copilot plugin for JetBrains IDEs, fixed in plugin version 1.17.0-251.
· Microsoft · Research by Microsoft Security Response Center
Microsoft published CVE-2026-83953 on 10 November 2026, a command injection flaw in the GitHub Copilot plugin for JetBrains IDEs that lets a local attacker with low privileges read information. Plugin version 1.17.0-251 fixes it.
01What happened
Microsoft published CVE-2026-83953 on 10 November 2026 as part of its November release, naming the GitHub Copilot plugin for JetBrains IDEs. Microsoft is the assigning authority and credits no outside researcher. GitHub's advisory database mirrored the record the same day, where it carries a moderate label and the same score.
02How it works
The weakness is classed as CWE-77, improper neutralization of special elements used in a command, and the stated effect is that an authorized attacker can disclose information locally. The published vector, AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N, means a caller who already has a low-privileged local account, needs no user interaction, and gains high impact on confidentiality only. Which command path accepts the unescaped input is not described.
03Who is affected
Plugin versions from 1.0.0 up to, but not including, 1.17.0-251 are listed as affected, across the JetBrains IDEs the plugin supports. Developer workstations carry the exposure, because the attack is local and the impact is reading data the plugin can reach.
04What to do
Update the GitHub Copilot plugin in every JetBrains IDE to 1.17.0-251 or later, the first version Microsoft lists as unaffected. Shared and multi-user developer hosts deserve the update first, since a low-privileged local account is all the flaw needs.
Sources 3 links, all fetched
- 1msrc.microsoft.comMicrosoft Advisory
- 2github.comGitHub Advisory
- 3cveawg.mitre.orgCVE Record