{"id":"CVE-2026-19671","state":"PUBLISHED","title":"Improper handling of highly compressed data (data amplification) in CISA Malcolm","description":"Malcolm's upload-processing pipeline (scripts/safe-extract.py) enforces entry-count, nesting-depth, and total-uncompressed-byte limits when extracting container archives (zip/tar/rar/7z via libarchive), but those limits are not applied when the uploaded file is a single-stream compressed format (.gz, .bz2, .xz, .lzma, .lz) that isn't a .tar.*-style archive. Any authenticated user permitted to upload PCAP/log files can upload a small, highly compressible file (e.g. a gzip bomb) that decompresses to an effectively unbounded size on disk, exhausting the shared Docker volume used by OpenSearch, Logstash, Arkime, and Zeek, and disrupting the platform for all users.","publishedAt":"2026-08-18T19:11:58.230Z","updatedAt":"2026-08-18T19:45:58.424Z","severity":{"score":7.1,"label":"High","version":"4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","source":"icscert"},"assigner":"icscert","products":["CISAgov Malcolm"],"affected":[{"vendor":"CISAgov","product":"Malcolm","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThanOrEqual":"26.07.1","versionType":"custom"}]}],"references":["https://www.cisa.gov/news-events/ics-advisories/icsa-26-230-01","https://github.com/cisagov/Malcolm/security/advisories/GHSA-f2v6-8cj4-mhr6"],"weaknesses":["CWE-409"],"ingestedAt":"2026-10-29T20:11:10.572Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/19xxx/CVE-2026-19671.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-19671","state":"PUBLISHED","datePublished":"2026-08-18T19:11:58.230Z","dateUpdated":"2026-08-18T19:45:58.424Z","assignerShortName":"icscert","assignerOrgId":"7d14cffa-0d7d-4270-9dc0-52cabd5a23a6","dateReserved":"2026-08-12T21:15:03.423Z"},"containers":{"cna":{"title":"Improper handling of highly compressed data (data amplification) in CISA Malcolm","descriptions":[{"lang":"en","value":"Malcolm's upload-processing pipeline (scripts/safe-extract.py) enforces entry-count, nesting-depth, and total-uncompressed-byte limits when extracting container archives (zip/tar/rar/7z via libarchive), but those limits are not applied when the uploaded file is a single-stream compressed format (.gz, .bz2, .xz, .lzma, .lz) that isn't a .tar.*-style archive. Any authenticated user permitted to upload PCAP/log files can upload a small, highly compressible file (e.g. a gzip bomb) that decompresses to an effectively unbounded size on disk, exhausting the shared Docker volume used by OpenSearch, Logstash, Arkime, and Zeek, and disrupting the platform for all users."}],"affected":[{"vendor":"CISAgov","product":"Malcolm","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThanOrEqual":"26.07.1","versionType":"custom"}]}],"references":[{"url":"https://www.cisa.gov/news-events/ics-advisories/icsa-26-230-01","tags":["government-resource"]},{"url":"https://github.com/cisagov/Malcolm/security/advisories/GHSA-f2v6-8cj4-mhr6"}],"metrics":[{"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}],"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"LOW","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":7.1,"vectorString":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N"}},{"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}],"cvssV3_1":{"version":"3.1","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"HIGH","baseSeverity":"MEDIUM","baseScore":6.5,"vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"}},{"other":{"type":"ssvc","content":{"options":[{"Exploitation":"poc"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CNA","version":"2.0.3"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-409","lang":"en","description":"CWE-409 Improper handling of highly compressed data (data amplification)","type":"CWE"}]}],"providerMetadata":{"shortName":"icscert","orgId":"7d14cffa-0d7d-4270-9dc0-52cabd5a23a6","dateUpdated":"2026-08-18T19:11:58.230Z"},"solutions":[{"lang":"en","value":"Malcolm version 26.08.0 addresses this issue. For more information, see  https://github.com/cisagov/Malcolm/security/advisories/GHSA-f2v6-8cj4-mhr6 .","supportingMedia":[{"type":"text/html","base64":false,"value":"Malcolm version 26.08.0 addresses this issue. For more information, see&nbsp;<a href=\"https://github.com/cisagov/Malcolm/security/advisories/GHSA-f2v6-8cj4-mhr6\" target=\"_blank\">https://github.com/cisagov/Malcolm/security/advisories/GHSA-f2v6-8cj4-mhr6</a>.&nbsp;"}]}],"credits":[{"lang":"en","value":"tinyb0y","type":"finder"}],"source":{"discovery":"UNKNOWN"},"x_generator":{"engine":"Vulnogram 1.0.4"}},"adp":[{"title":"CISA ADP Vulnrichment","references":[{"url":"https://github.com/cisagov/Malcolm/security/advisories/GHSA-f2v6-8cj4-mhr6","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-08-18T19:42:34.846884Z","id":"CVE-2026-19671","options":[{"Exploitation":"poc"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-08-18T19:45:58.424Z"}}]}}}