CVE-2026-70464: rsync 2.0.0 < 3.5.0 Connection Slot Exhaustion DoS via Handshake Stall
rsync 2.0.0 < 3.5.0 Connection Slot Exhaustion DoS via Handshake Stall
Other sources
rsync daemon 2.0.0 before 3.5.0 contains a denial of service vulnerability that allows unauthenticated remote attackers to exhaust daemon connection slots by stalling the handshake process before or after module selection without triggering the I/O timeout. Attackers can open many simultaneous connections and trickle data at the minimum rate to avoid timeout, or stall entirely before module selection where no timeout applies, consuming all available connection slots and denying service to legitimate clients.
— NVD
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 3.5.0-1
Event History
Frequently Asked Questions
What is the severity of CVE-2026-70464?
CVE-2026-70464 has a severity score of 7.5, categorized as high.
How do I fix CVE-2026-70464?
To resolve CVE-2026-70464, upgrade rsync to version 3.5.0 or later.
What type of vulnerability is CVE-2026-70464?
CVE-2026-70464 is a denial of service vulnerability that affects the rsync daemon.
Can CVE-2026-70464 be exploited remotely?
Yes, CVE-2026-70464 can be exploited by unauthenticated remote attackers.
What impact does CVE-2026-70464 have on the server?
CVE-2026-70464 allows attackers to exhaust daemon connection slots, causing a denial of service.