CVE-2026-70453

high

Description

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.

References

https://www.vulncheck.com/advisories/rsync-algorithmic-complexity-dos-via-hash-search

https://github.com/RsyncProject/rsync/security/advisories/GHSA-8x5r-mjx8-83hv

https://github.com/RsyncProject/rsync/releases/tag/v3.5.0

Details

Source: Mitre, NVD

Published: 2026-08-13

Updated: 2026-08-13

Risk Information

CVSS v2

Base Score: 7.8

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:C

Severity: High

CVSS v3

Base Score: 7.5

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

Severity: High

CVSS v4

Base Score: 8.7

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Severity: High