{"affected":[{"defaultStatus":"unaffected","ecosystem":"otp","packageName":"hex","product":"hex","source":"CNA: EEF","vendor":"hexpm","versions":[{"lessThan":"2.5.2","status":"affected","version":"0.20.2","versionType":"semver"}]},{"defaultStatus":"unaffected","ecosystem":"github","packageName":"hexpm/hex","product":"hex","source":"CNA: EEF","vendor":"hexpm","versions":[{"changes":[{"at":"8a14632ca6ba8a8afd2a3f2098bc267c13e13d93","status":"unaffected"},{"at":"69489f8b74213f03db10169e6e5407e6d5fee512","status":"unaffected"}],"lessThan":"*","status":"affected","version":"d1f5a085d9d4748e1f7d195e4bc39ebd77c28d9c","versionType":"git"}]}],"cveId":"CVE-2026-105280","cwes":["CWE-354"],"description":"Improper Validation of Integrity Check Value vulnerability in hexpm hex allows a package mirror to substitute the tarball that mix hex.package fetch PACKAGE VERSION --output - writes to standard output.\n\nHex compares a fetched tarball's inner and outer checksums with the repository's signed registry before writing it to a file or unpacking it. The standard output branch of mix hex.package fetch writes the bytes returned by Hex.SCM.fetch/3 without that comparison, and Hex.SCM.fetch/3 doesn't verify freshly downloaded tarballs itself. When a mirror configured with HEX_MIRROR_URL or mirror_url serves altered bytes, the command prints them and exits successfully, while the same fetch with --output FILE fails with a checksum mismatch.\n\nHex also prints diagnostics to standard output while the command runs: the body of a failed HTTP response from the update check or a registry fetch, and API warnings from the x-hex-message header. A mirror that answers one of those requests with an error whose body is a tar archive gets that archive written to standard output ahead of the verified tarball, so a pipeline that unpacks standard output extracts the mirror's files. This happens even when the checksum check then fails, because the archive is already on standard output.\n\nThis issue affects hex: from 0.20.2 before 2.5.2.","epss":{"date":"2026-11-10","percentile":0.11363,"score":0.00211},"exploits":[],"kev":null,"metrics":[{"score":6.9,"severity":"medium","source":"CNA: EEF","vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:N/VI:H/VA:N/SC:N/SI:H/SA:N","version":"4.0"}],"modifiedAt":1794405780287,"publishedAt":1791819014126,"references":[{"source":"CNA: EEF","tags":["related","vendor-advisory"],"url":"https://github.com/hexpm/hex/security/advisories/GHSA-98jr-23pm-vj7c"},{"source":"CNA: EEF","tags":["related"],"url":"https://cna.erlef.org/cves/CVE-2026-105280.html"},{"source":"CNA: EEF","tags":["related"],"url":"https://osv.dev/vulnerability/EEF-CVE-2026-105280"},{"source":"CNA: EEF","tags":["related"],"url":"https://github.com/hexpm/hex/commit/d1f5a085d9d4748e1f7d195e4bc39ebd77c28d9c"},{"source":"CNA: EEF","tags":["patch"],"url":"https://github.com/hexpm/hex/commit/8a14632ca6ba8a8afd2a3f2098bc267c13e13d93"},{"source":"CNA: EEF","tags":["patch"],"url":"https://github.com/hexpm/hex/commit/69489f8b74213f03db10169e6e5407e6d5fee512"}],"remediation":[{"kind":"fix","source":"CNA: EEF","text":"Upgrade Hex to 2.5.2 or later, for example with mix local.hex. mix hex.package fetch PACKAGE VERSION --output - then verifies the registry checksum before writing the tarball to standard output and prints its messages to standard error."},{"kind":"workaround","source":"CNA: EEF","text":"Write the tarball to a file with --output FILE, which verifies the checksums, and read that file instead of standard output."},{"kind":"fix","source":"CNA: EEF","text":"The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches.","url":"https://github.com/hexpm/hex/commit/8a14632ca6ba8a8afd2a3f2098bc267c13e13d93"},{"kind":"fix","source":"CNA: EEF","text":"The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches.","url":"https://github.com/hexpm/hex/commit/69489f8b74213f03db10169e6e5407e6d5fee512"}],"revision":"eaf38ae0c900ef9213bd79fc5be0601fa35ac23adbfde1d4b297153fc2a593cf","sources":[{"modifiedAt":1794405780287,"name":"CNA: EEF","retrievedAt":1794409703681,"url":"https://www.cve.org/CVERecord?id=CVE-2026-105280"},{"modifiedAt":null,"name":"FIRST EPSS","retrievedAt":1794409727386,"url":"https://api.first.org/data/v1/epss?cve=CVE-2026-105280"}],"ssvc":{"assessedAt":1792172117920,"automatable":"no","exploitation":"none","source":"ADP: CISA-ADP","technicalImpact":"partial"},"status":"published","title":"Hex writes unverified package tarballs to standard output in mix hex.package fetch","updatedAt":1794409727386}