CVE-2026-70453

HIGH 7.5

rsync < 3.5.0 Algorithmic Complexity DoS via hash_search()

CVSS Score

7.5

EPSS Score

0.0%

EPSS Percentile

0th

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.

CWE	CWE-407
Vendor	rsyncproject
Product	rsync
Published	Aug 13, 2026

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CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Affected Versions

RsyncProject / rsync

0 ≤ 3.4.4

References

NVD ↗ CVE.org ↗ EPSS Data ↗

github.com: https://github.com/RsyncProject/rsync/security/advisories/GHSA-8x5r-mjx8-83hv github.com: https://github.com/RsyncProject/rsync/releases/tag/v3.5.0 vulncheck.com: https://www.vulncheck.com/advisories/rsync-algorithmic-complexity-dos-via-hash-search

Credits

heyciao dr-who