CVE-2026-70453: rsync < 3.5.0 Algorithmic Complexity DoS via hash_search()
CSIRTS triage
- What
- An algorithmic complexity vulnerability in the hash_search() function allows remote attackers to cause a denial of service through CPU exhaustion.
- Who is affected
- rsync daemon or server instances running versions prior to 3.5.0 that process untrusted file lists.
- Urgency
- High severity; exploitable remotely without authentication and causes service unavailability.
- Action
- Upgrade rsync to version 3.5.0 or later immediately.
AI-assisted analysis generated from the source advisory — verify against the original.
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Details
Original advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-70453
Exploitation outlook
EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.
- Low exploitation riskCVE-2026-704530.53% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 42% of all EPSS-scored CVEs.
Referenced CVEs
| CVE | CSIRTS overview | External |
|---|---|---|
| CVE-2026-70453 | coverage & exploitation status | NVD · CVE.org |
Same CVEs, other sources
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