Affects GitHub Enterprise Server, a widely deployed enterprise code platform; allows injected workflows that can access Actions secrets — high-impact across organizations.
CVE-2026-15343
Path traversal in Dependabot allows writing malicious GitHub Actions workflows.
Is CVE-2026-15343 being exploited?
Not confirmed. CVE-2026-15343 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 0.57% probability of exploitation in the next 30 days.
How severe is CVE-2026-15343?
CVE-2026-15343 is rated High with a CVSS score of 8.6. 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-2026-15343?
Yes. A fix has been recorded for CVE-2026-15343. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-15343 affect?
CVE-2026-15343 affects GitHub Enterprise Server < 3.22, Dependabot updater container, Repositories using pull_request_target or auto-merge. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-15343?
Upgrade to fixed GES versions and rotate/seal Actions secrets; audit workflows.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Write arbitrary repo files (including .github/workflows) to inject workflows that run and access/exfiltrate GitHub Actions secrets.
Immediate action required
- affected>= 3.17.0 and <= 3.17.17
- affected>= 3.18.0 and <= 3.18.11
- affected>= 3.19.0 and <= 3.19.8
- affected>= 3.20.0 and <= 3.20.4
- affected>= 3.21.0 and <= 3.21.2
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.