PatchTheCEVCVE-2026-70453: rsync before 3.5.0 contains an algorithmic complexity vulnerability in the hash_search() function that allows
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This month
HIGH 7.5REMOTE
CVE-2026-70453 is a high-severity flaw (CVSS 7.5) affecting affected software. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
rsync before 3.5.0 contains an algorithmic complexity vulnerability in the hash_search() function that allows a remote attacker to cause a denial of service by delivering a carefully constructed file list. A sender can exploit the quadratic-time worst-case behavior in hash lookups to exhaust receiver CPU resources with a modest number of crafted entries, causing a sustained denial of service.
Why this priority
- High severity
- Remotely exploitable, no login, no user action
A fixed release or distro patch exists.
Risk facts
| CVSS score | 7.5 (High) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | None |
| User interaction | None |
| EPSS exploit chance | 0.5% (top 56%) |
| CISA exploited list | No |
| Weakness | CWE-407 |
| Published | 2026-08-13 |
| Last modified | 2026-10-23 |
Publisher (CNA): VulnCheck
Timeline
- Published CVE record published
- Updated Record last modified
Exact fixes by distribution
Fedora 46 · wasmedge · FIXED · 0.18.1-1.fc46 · FEDORA-2026-4c27216e39 · source
sudo dnf upgrade --advisory=FEDORA-2026-4c27216e39
Debian 12 · rsync · NO FIX YET
Debian 13 · rsync · FIXED · 3.5.0+ds1-0+deb13u1
sudo apt update && sudo apt install --only-upgrade rsync
dpkg --compare-versions "$(dpkg-query -W -f='${Version}' rsync)" ge "3.5.0+ds1-0+deb13u1" && echo PATCHED || echo STILL-VULNERABLE
RHEL 10 · rsync · FIXED · rsync-3.5.0-3.el10_2
sudo dnf upgrade --advisory=RHSA-2026:67463
rpm -q rsync
RHEL 8 · rsync · FIXED · rsync-3.1.3-28.el8_10
sudo dnf upgrade --advisory=RHSA-2026:74095
rpm -q rsync
RHEL 9 · rsync · FIXED · rsync-3.2.7-1.el9_8
sudo dnf upgrade --advisory=RHSA-2026:67462
rpm -q rsync
RHEL 6 · rsync · NO FIX YET
RHEL 7 · rsync · NO FIX YET
Alpine 3.21 · rsync · FIXED · rsync-3.5.0-r0
apk add --upgrade rsync
apk info -v rsync
Alpine 3.22 · rsync · FIXED · rsync-3.5.0-r0
apk add --upgrade rsync
apk info -v rsync
Alpine 3.23 · rsync · FIXED · rsync-3.5.0-r0
apk add --upgrade rsync
apk info -v rsync
Alpine 3.24 · rsync · FIXED · rsync-3.5.0-r0
apk add --upgrade rsync
apk info -v rsync
sudo dnf update --advisory=ALAS2023-2026-3131
sudo yum update --advisory=ALAS2-2026-3945
Advisories and coverage
Official advisories
- Amazon Linux 2 ALAS: ALAS2-2026-3945 (important): rsync 2026-09-28
Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.