rsync < 3.5.0 Algorithmic Complexity DoS via hash_search() (CVE-2026-70453) | HOL Guard CVE

High · CVSS 7.5CVE-2026-70453

rsync < 3.5.0 Algorithmic Complexity DoS via hash_search()

Answer in brief

CVE-2026-70453 records a High severity (CVSS 7.5) vulnerability in rsync < 3.5.0 Algorithmic Complexity DoS via hash_search(). The current sources do not mark it as known exploited. The current feed maps RsyncProject/rsync (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Aug 13, 2026Updated Sep 8, 2026Source checked Sep 27, 2026First seen by HOL Aug 13, 2026Material review Sep 8, 2026

Upstream Advisory

Key facts

Risk: High · CVSS 7.5
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Not reported

Why this deserves its current priority

CVSS is 7.5. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps RsyncProject/rsync (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
RsyncProject/rsyncgeneric	0	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for RsyncProject/rsync.
Review the reported fix. Monitor this advisory for an available fix and review any installs of the affected package.

Evidence timeline and material changes

Published upstream
Aug 13, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 8, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Aug 13, 2026

Sources and claim methodology

Upstream source 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.

Quoted source text, attributed separately from HOL analysis.