{"id":"UBUNTU-CVE-2026-50012","details":"Squid is a caching proxy for the Web. Prior to 7.6, due to an improper input validation bug in cache digest reply handling (peerDigestSwapInMask in src/peer_digest.cc), Squid is vulnerable to a heap-based buffer overflow: a cache digest's on-the-wire size may be larger than the mask_size declared within the digest, so a trusted peer sending a maliciously crafted reply to a cache_digest request message can trigger the overflow. This attack is limited to Squid instances compiled with the --enable-cache-digests option and configured with cache_peer entries. This issue is fixed in version 7.6.","modified":"2026-07-29T10:18:19.116385004Z","published":"2026-06-12T00:00:00Z","related":["USN-8435-1"],"upstream":["CVE-2026-50012"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-50012"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-50012"},{"type":"REPORT","url":"https://www.openwall.com/lists/oss-security/2026/06/12/1"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-8435-1"}],"affected":[{"package":{"name":"squid3","ecosystem":"Ubuntu:Pro:16.04:LTS","purl":"pkg:deb/ubuntu/squid3?arch=source&distro=esm-infra%2Fxenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.3.8-1ubuntu16","3.3.8-1ubuntu17","3.5.12-1ubuntu6","3.5.12-1ubuntu7","3.5.12-1ubuntu7.1","3.5.12-1ubuntu7.2","3.5.12-1ubuntu7.3","3.5.12-1ubuntu7.4","3.5.12-1ubuntu7.5","3.5.12-1ubuntu7.6","3.5.12-1ubuntu7.7","3.5.12-1ubuntu7.8","3.5.12-1ubuntu7.9","3.5.12-1ubuntu7.10","3.5.12-1ubuntu7.11","3.5.12-1ubuntu7.12","3.5.12-1ubuntu7.13","3.5.12-1ubuntu7.14","3.5.12-1ubuntu7.15","3.5.12-1ubuntu7.16","3.5.12-1ubuntu7.16+esm1","3.5.12-1ubuntu7.16+esm2","3.5.12-1ubuntu7.16+esm3","3.5.12-1ubuntu7.16+esm4","3.5.12-1ubuntu7.16+esm5","3.5.12-1ubuntu7.16+esm6"],"ecosystem_specific":{"binaries":[{"binary_version":"3.5.12-1ubuntu7.16+esm6","binary_name":"squid"},{"binary_name":"squid-cgi","binary_version":"3.5.12-1ubuntu7.16+esm6"},{"binary_name":"squid-common","binary_version":"3.5.12-1ubuntu7.16+esm6"},{"binary_name":"squid-purge","binary_version":"3.5.12-1ubuntu7.16+esm6"},{"binary_name":"squid3","binary_version":"3.5.12-1ubuntu7.16+esm6"},{"binary_name":"squidclient","binary_version":"3.5.12-1ubuntu7.16+esm6"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-50012.json"}},{"package":{"name":"squid3","ecosystem":"Ubuntu:Pro:18.04:LTS","purl":"pkg:deb/ubuntu/squid3?arch=source&distro=esm-infra%2Fbionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.5.23-5ubuntu1","3.5.23-5ubuntu2","3.5.27-1ubuntu1","3.5.27-1ubuntu1.1","3.5.27-1ubuntu1.2","3.5.27-1ubuntu1.3","3.5.27-1ubuntu1.4","3.5.27-1ubuntu1.5","3.5.27-1ubuntu1.6","3.5.27-1ubuntu1.7","3.5.27-1ubuntu1.8","3.5.27-1ubuntu1.9","3.5.27-1ubuntu1.10","3.5.27-1ubuntu1.11","3.5.27-1ubuntu1.12","3.5.27-1ubuntu1.13","3.5.27-1ubuntu1.14","3.5.27-1ubuntu1.14+esm1","3.5.27-1ubuntu1.14+esm2","3.5.27-1ubuntu1.14+esm3","3.5.27-1ubuntu1.14+esm4","3.5.27-1ubuntu1.14+esm5"],"ecosystem_specific":{"binaries":[{"binary_name":"squid","binary_version":"3.5.27-1ubuntu1.14+esm5"},{"binary_name":"squid-cgi","binary_version":"3.5.27-1ubuntu1.14+esm5"},{"binary_name":"squid-common","binary_version":"3.5.27-1ubuntu1.14+esm5"},{"binary_name":"squid-purge","binary_version":"3.5.27-1ubuntu1.14+esm5"},{"binary_name":"squid3","binary_version":"3.5.27-1ubuntu1.14+esm5"},{"binary_name":"squidclient","binary_version":"3.5.27-1ubuntu1.14+esm5"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-50012.json"}},{"package":{"name":"squid","ecosystem":"Ubuntu:Pro:20.04:LTS","purl":"pkg:deb/ubuntu/squid?arch=source&distro=esm-infra%2Ffocal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.8-1ubuntu2","4.8-1ubuntu3","4.9-2ubuntu1","4.9-2ubuntu2","4.9-2ubuntu3","4.9-2ubuntu4","4.10-1ubuntu1","4.10-1ubuntu1.1","4.10-1ubuntu1.2","4.10-1ubuntu1.3","4.10-1ubuntu1.4","4.10-1ubuntu1.5","4.10-1ubuntu1.6","4.10-1ubuntu1.7","4.10-1ubuntu1.8","4.10-1ubuntu1.9","4.10-1ubuntu1.10","4.10-1ubuntu1.11","4.10-1ubuntu1.12","4.10-1ubuntu1.13","4.10-1ubuntu1.13+esm1","4.10-1ubuntu1.13+esm2"],"ecosystem_specific":{"binaries":[{"binary_name":"squid","binary_version":"4.10-1ubuntu1.13+esm2"},{"binary_name":"squid-cgi","binary_version":"4.10-1ubuntu1.13+esm2"},{"binary_version":"4.10-1ubuntu1.13+esm2","binary_name":"squid-common"},{"binary_version":"4.10-1ubuntu1.13+esm2","binary_name":"squid-purge"},{"binary_name":"squidclient","binary_version":"4.10-1ubuntu1.13+esm2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-50012.json"}},{"package":{"name":"squid","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/squid?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.9-0ubuntu0.22.04.7"}]}],"versions":["4.13-10ubuntu5","5.2-1ubuntu1","5.2-1ubuntu3","5.2-1ubuntu4","5.2-1ubuntu4.1","5.2-1ubuntu4.2","5.2-1ubuntu4.3","5.7-0ubuntu0.22.04.1","5.7-0ubuntu0.22.04.2","5.7-0ubuntu0.22.04.3","5.7-0ubuntu0.22.04.4","5.9-0ubuntu0.22.04.1","5.9-0ubuntu0.22.04.2","5.9-0ubuntu0.22.04.3","5.9-0ubuntu0.22.04.4","5.9-0ubuntu0.22.04.5"],"ecosystem_specific":{"binaries":[{"binary_name":"squid","binary_version":"5.9-0ubuntu0.22.04.7"},{"binary_name":"squid-cgi","binary_version":"5.9-0ubuntu0.22.04.7"},{"binary_name":"squid-common","binary_version":"5.9-0ubuntu0.22.04.7"},{"binary_name":"squid-openssl","binary_version":"5.9-0ubuntu0.22.04.7"},{"binary_name":"squid-purge","binary_version":"5.9-0ubuntu0.22.04.7"},{"binary_name":"squidclient","binary_version":"5.9-0ubuntu0.22.04.7"}],"availability":"No subscription required"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-50012.json"}},{"package":{"name":"squid","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/squid?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.14-0ubuntu0.24.04.4"}]}],"versions":["6.1-2ubuntu1","6.1-2ubuntu2","6.5-1ubuntu1","6.5-1ubuntu2","6.5-1ubuntu3","6.6-1ubuntu4","6.6-1ubuntu5","6.6-1ubuntu5.1","6.10-0ubuntu0.24.04.1","6.13-0ubuntu0.24.04.1","6.13-0ubuntu0.24.04.2","6.13-0ubuntu0.24.04.3","6.14-0ubuntu0.24.04.1","6.14-0ubuntu0.24.04.2"],"ecosystem_specific":{"binaries":[{"binary_version":"6.14-0ubuntu0.24.04.4","binary_name":"squid"},{"binary_name":"squid-cgi","binary_version":"6.14-0ubuntu0.24.04.4"},{"binary_version":"6.14-0ubuntu0.24.04.4","binary_name":"squid-common"},{"binary_name":"squid-openssl","binary_version":"6.14-0ubuntu0.24.04.4"},{"binary_name":"squid-purge","binary_version":"6.14-0ubuntu0.24.04.4"},{"binary_name":"squidclient","binary_version":"6.14-0ubuntu0.24.04.4"}],"availability":"No subscription required"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-50012.json"}},{"package":{"name":"squid","ecosystem":"Ubuntu:25.10","purl":"pkg:deb/ubuntu/squid?arch=source&distro=questing"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.14-0ubuntu0.25.10.4"}]}],"versions":["6.13-1ubuntu1","6.13-1ubuntu2","6.13-1ubuntu3","6.13-1ubuntu4","6.13-1ubuntu4.1","6.14-0ubuntu0.25.10.1","6.14-0ubuntu0.25.10.2"],"ecosystem_specific":{"availability":"No subscription 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subscription required"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-50012.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:H"},{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:H"},{"type":"Ubuntu","score":"medium"}]}