{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-70455","assignerOrgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","state":"PUBLISHED","assignerShortName":"VulnCheck","dateReserved":"2026-08-04T14:52:23.814Z","datePublished":"2026-08-13T14:45:11.164Z","dateUpdated":"2026-08-14T19:45:47.934Z"},"containers":{"cna":{"providerMetadata":{"orgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","shortName":"VulnCheck","dateUpdated":"2026-08-14T16:51:20.314Z"},"title":"rsync 3.4.2 < 3.5.0 DoS via --zt Zstandard Compression Thread Exhaustion","datePublic":"2026-08-12T00:00:00.000Z","problemTypes":[{"descriptions":[{"lang":"en","cweId":"CWE-770","description":"CWE-770 Allocation of Resources Without Limits or Throttling","type":"CWE"}]}],"affected":[{"vendor":"RsyncProject","product":"rsync","repo":"https://github.com/RsyncProject/rsync","versions":[{"status":"affected","version":"3.4.2","lessThanOrEqual":"3.4.4","versionType":"semver"},{"status":"unaffected","version":"3.5.0","versionType":"semver"}],"defaultStatus":"unaffected","packageURL":"pkg:github/RsyncProject/rsync"}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:samba:rsync:*:*:*:*:*:*:*:*","versionStartIncluding":"3.4.2","versionEndIncluding":"3.4.4"}]}]}],"descriptions":[{"lang":"en","value":"rsync 3.4.2 before 3.5.0 contains a denial of service vulnerability that allows a remote sender to exhaust system resources by specifying the --zt short alias for --compress-threads, which bypasses the refuse options directive's string matching on long option names. Attackers can specify --zt=N with a large value to spawn an unbounded number of Zstandard worker threads on the receiver, exhausting available thread and memory resources.","supportingMedia":[{"type":"text/html","base64":false,"value":"<p>rsync 3.4.2 before 3.5.0&nbsp;contains a denial of service vulnerability that allows a remote sender to exhaust system resources by specifying the --zt short alias for --compress-threads, which bypasses the refuse options directive's string matching on long option names. Attackers can specify --zt=N with a large value to spawn an unbounded number of Zstandard worker threads on the receiver, exhausting available thread and memory resources.</p>"}]}],"references":[{"url":"https://github.com/RsyncProject/rsync/security/advisories/GHSA-rjvj-qgqg-cvx9","name":"GitHub Security Advisory (GHSA-rjvj-qgqg-cvx9)","tags":["vendor-advisory"]},{"url":"https://github.com/RsyncProject/rsync/releases/tag/v3.5.0","name":"rsync 3.5.0 Release Notes","tags":["release-notes"]},{"url":"https://www.vulncheck.com/advisories/rsync-dos-via-zt-zstandard-compression-thread-exhaustion","tags":["third-party-advisory"]}],"metrics":[{"format":"CVSS","scenarios":[{"lang":"en","value":"Remote sender specifies --zt=N (Zstandard short alias not covered by refuse options) to spawn unbounded worker threads on the receiver (VA:H)."}],"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"NONE","subConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE","subIntegrityImpact":"NONE","vulnAvailabilityImpact":"HIGH","subAvailabilityImpact":"NONE","exploitMaturity":"NOT_DEFINED","Safety":"NOT_DEFINED","Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","valueDensity":"NOT_DEFINED","vulnerabilityResponseEffort":"NOT_DEFINED","providerUrgency":"NOT_DEFINED","version":"4.0","baseSeverity":"HIGH","baseScore":8.7,"vectorString":"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"}},{"format":"CVSS","scenarios":[{"lang":"en","value":"CVSS 3.1 reference score."}],"cvssV3_1":{"version":"3.1","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"HIGH","baseSeverity":"HIGH","baseScore":7.5,"vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"}}],"credits":[{"lang":"en","value":"fcasal","type":"finder"}],"source":{"discovery":"EXTERNAL"},"x_generator":{"engine":"Vulnogram 1.0.4"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-08-14T18:30:20.676739Z","id":"CVE-2026-70455","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-08-14T19:45:47.934Z"}}]}}