{"id":"UBUNTU-CVE-2026-105280","details":"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. Hex 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. Hex 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. This issue affects hex: from 0.20.2 before 2.5.2.","modified":"2026-10-17T12:59:46.904919641Z","published":"2026-10-15T00:00:00Z","upstream":["CVE-2026-105280"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-105280"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-105280"},{"type":"REPORT","url":"https://cna.erlef.org/cves/CVE-2026-105280.html"},{"type":"REPORT","url":"https://github.com/hexpm/hex/commit/69489f8b74213f03db10169e6e5407e6d5fee512"},{"type":"REPORT","url":"https://github.com/hexpm/hex/commit/8a14632ca6ba8a8afd2a3f2098bc267c13e13d93"},{"type":"REPORT","url":"https://github.com/hexpm/hex/commit/d1f5a085d9d4748e1f7d195e4bc39ebd77c28d9c"},{"type":"REPORT","url":"https://github.com/hexpm/hex/security/advisories/GHSA-98jr-23pm-vj7c"},{"type":"REPORT","url":"https://osv.dev/vulnerability/EEF-CVE-2026-105280"}],"affected":[{"package":{"name":"erlang-hex","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/erlang-hex?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.0.5-1"],"ecosystem_specific":{"binaries":[{"binary_name":"erlang-hex","binary_version":"2.0.5-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-105280.json"}},{"package":{"name":"erlang-hex","ecosystem":"Ubuntu:26.10","purl":"pkg:deb/ubuntu/erlang-hex?arch=source&distro=stonking"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.0.6-2build1","2.5.1-2"],"ecosystem_specific":{"binaries":[{"binary_name":"erlang-hex","binary_version":"2.5.1-2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-105280.json"}},{"package":{"name":"erlang-hex","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/erlang-hex?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.0.6-2","2.0.6-2build1"],"ecosystem_specific":{"binaries":[{"binary_name":"erlang-hex","binary_version":"2.0.6-2build1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-105280.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"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"},{"type":"Ubuntu","score":"medium"}]}