CVE-2026-56004
RCE via shellcode injection in mercurial obs tar_scm service before 0.12.4.
Is CVE-2026-56004 being exploited?
Not confirmed. CVE-2026-56004 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 0.66% probability of exploitation in the next 30 days.
How severe is CVE-2026-56004?
CVE-2026-56004 is rated Critical with a CVSS score of 10.0. 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-2026-56004?
Yes. A fix has been recorded for CVE-2026-56004. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-56004 affect?
CVE-2026-56004 affects Mercurial obs tar_scm source service (pre-0.12.4). Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-56004?
Upgrade to 0.12.4+; audit _service file usage.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Remote code execution via crafted _service file to run code as the service/local user.
Immediate action required
- affected< 0.12.4
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.