CVE-2026-34042
RCE in act local GitHub Actions runner via insecure cache server (pre-0.2.86).
Is CVE-2026-34042 being exploited?
Not confirmed. CVE-2026-34042 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 0.46% probability of exploitation in the next 30 days.
How severe is CVE-2026-34042?
CVE-2026-34042 is rated High with a CVSS score of 8.2. 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-2026-34042?
Yes. A fix has been recorded for CVE-2026-34042. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-34042 affect?
CVE-2026-34042 affects act local GitHub Actions runner <= 0.2.85, Dockerized CI environments using act. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-34042?
Upgrade to v0.2.86+ immediately
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Remote attacker can create/retrieve caches; with guessed keys, injects files enabling arbitrary code execution inside the act Docker container.
Patch when possible
- affected< 0.2.86
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.