CVE-2026-21516
Command injection in GitHub Copilot enables remote code execution.
Is CVE-2026-21516 being exploited?
Not confirmed. CVE-2026-21516 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.82% probability of exploitation in the next 30 days.
How severe is CVE-2026-21516?
CVE-2026-21516 is rated High with a CVSS score of 8.8. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-21516?
Yes. A fix has been recorded for CVE-2026-21516. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-21516 affect?
CVE-2026-21516 affects GitHub Copilot. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-21516?
Patch when released; restrict Copilot access; monitor for exploits.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Remote code execution via network; attacker can run arbitrary commands on Copilot servers.
Patch when possible
- affected>= 1.0.0 and < 1.5.63
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.