CVE-2026-70453
Algorithmic complexity in rsync <3.5.0 allows remote CPU exhaustion and sustained DoS.
Is CVE-2026-70453 being exploited?
Not confirmed. CVE-2026-70453 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 0.53% probability of exploitation in the next 30 days.
How severe is CVE-2026-70453?
CVE-2026-70453 is rated High with a CVSS score of 8.7. 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-2026-70453?
Yes. A fix has been recorded for CVE-2026-70453. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-70453 affect?
CVE-2026-70453 affects rsync < 3.5.0 (receiver/daemon), Backup servers using rsync, NAS devices using rsync, CI/CD and sync pipelines using rsync. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-70453?
Upgrade rsync to >=3.5.0; restrict/untrusted senders and network access until patched.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Remote attacker can send a crafted file list to receivers, triggering quadratic hash lookups and exhausting CPU, causing sustained Denial of Service.
Patch when possible
- affected<= 3.4.4
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.