{"dataType":"CVE_RECORD","cveMetadata":{"cveId":"CVE-2026-40395","assignerOrgId":"8254265b-2729-46b6-b9e3-3dfca2d5bfca","state":"PUBLISHED","assignerShortName":"mitre","dateReserved":"2026-04-12T19:21:08.847Z","datePublished":"2026-04-12T19:21:09.265Z","dateUpdated":"2026-04-13T15:45:30.791Z"},"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Varnish Enterprise","vendor":"varnish-software","versions":[{"lessThan":"6.0.16r12","status":"affected","version":"6.0.9r5","versionType":"custom"}]}],"descriptions":[{"lang":"en","value":"Varnish Enterprise before 6.0.16r12 allows a \"workspace overflow\" denial of service (daemon panic) for shared VCL. The headerplus.write_req0() function from vmod_headerplus updates the underlying req0, which is normally the original read-only request from which req is derived (readable and writable from VCL). This is useful in the active VCL, after amending req, to prepare a refined req0 before switching to a different VCL with the return (vcl(<label>)) action. This is for example how the Varnish Controller operates shared VCL deployments. If the amended req contained too many header fields for req0, this would have resulted in a workspace overflow that would in turn trigger a panic and crash the Varnish Enterprise server. This could be used as a Denial of Service attack vector by malicious clients."}],"metrics":[{"cvssV3_1":{"attackComplexity":"HIGH","attackVector":"NETWORK","availabilityImpact":"LOW","baseScore":4,"baseSeverity":"MEDIUM","confidentialityImpact":"NONE","integrityImpact":"NONE","privilegesRequired":"NONE","scope":"CHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:N/A:L","version":"3.1"},"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}]}],"problemTypes":[{"descriptions":[{"cweId":"CWE-770","description":"CWE-770 Allocation of Resources Without Limits or Throttling","lang":"en","type":"CWE"}]}],"providerMetadata":{"orgId":"8254265b-2729-46b6-b9e3-3dfca2d5bfca","shortName":"mitre","dateUpdated":"2026-04-12T19:33:44.790Z"},"references":[{"url":"https://docs.varnish-software.com/security/VEV00003/"}],"x_generator":{"engine":"CVE-Request-form 0.0.1"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:varnish-software:varnish_enterprise:*:*:*:*:*:*:*:*","versionStartIncluding":"6.0.9r5","versionEndExcluding":"6.0.16r12"}]}]}]},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-04-13T15:45:24.491498Z","id":"CVE-2026-40395","options":[{"Exploitation":"none"},{"Automatable":"no"},{"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":"2026-04-13T15:45:30.791Z"}}]},"dataVersion":"5.2"}