{"id":"CVE-2026-33526","summary":"Squid vulnerable to Denial of Service in ICP Request handling","details":"Squid is a caching proxy for the Web. Prior to version 7.5, due to heap Use-After-Free, Squid is vulnerable to Denial of Service when handling ICP traffic. This problem allows a remote attacker to perform a reliable and repeatable Denial of Service attack against the Squid service using ICP protocol. This attack is limited to Squid deployments that explicitly enable ICP support (i.e. configure non-zero `icp_port`). This problem _cannot_ be mitigated by denying ICP queries using `icp_access` rules. Version 7.5 contains a patch.","aliases":["GHSA-hpfx-h48q-gvwg"],"modified":"2026-08-12T15:33:24.769687Z","published":"2026-03-26T00:16:12.195Z","related":["ALSA-2026:6301","ALSA-2026:8119","ALSA-2026:8317"],"database_specific":{"cna_assigner":"GitHub_M","cwe_ids":["CWE-416","CWE-826"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/33xxx/CVE-2026-33526.json"},"references":[{"type":"WEB","url":"http://www.openwall.com/lists/oss-security/2026/03/25/2"},{"type":"WEB","url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-33526.json"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:10255"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:10256"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:10257"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:11901"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:20564"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:20565"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:20580"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:6301"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:8119"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:8317"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:8880"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:9220"},{"type":"ADVISORY","url":"https://access.redhat.com/security/cve/CVE-2026-33526"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/33xxx/CVE-2026-33526.json"},{"type":"ADVISORY","url":"https://github.com/squid-cache/squid/security/advisories/GHSA-hpfx-h48q-gvwg"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-33526"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2451574"},{"type":"FIX","url":"https://github.com/squid-cache/squid/commit/8a7d42f9d44befb8fcbbb619505587c8de6a1e91"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/squid-cache/squid","events":[{"introduced":"0"},{"fixed":"2e58fa81c730f29f6ec52ef8bd056e658e01d50c"},{"fixed":"8a7d42f9d44befb8fcbbb619505587c8de6a1e91"}],"database_specific":{"cpe":"cpe:2.3:a:squid-cache:squid:*:*:*:*:*:*:*:*","extracted_events":[{"introduced":"0"},{"fixed":"7.5"}],"source":["CPE_RANGE","REFERENCES"]}}],"versions":["SQUID_7_4","SQUID_7_3","SQUID_7_2","SQUID_7_1","SQUID_7_0_2","SQUID_7_0_1","6.0.0-20210527-master-snapshot","5.0.6-20210527-snapshot","4.15-20210527-snapshot","6.0.0-20210525-master-snapshot","5.0.6-20210525-snapshot","4.15-20210525-snapshot","6.0.0-20210524-master-snapshot","6.0.0-20210523-master-snapshot","6.0.0-20210522-master-snapshot","5.0.6-20210524-snapshot","5.0.6-20210523-snapshot","5.0.6-20210522-snapshot","4.15-20210524-snapshot","4.15-20210523-snapshot","4.15-20210522-snapshot","M-staged-PR365","M-staged-PR370","M-staged-PR376","M-staged-PR375","M-staged-PR373","M-staged-PR372","M-staged-PR319","M-staged-PR366","M-staged-PR351","M-staged-PR342","M-staged-PR364","M-staged-PR359","M-staged-PR348","M-staged-PR345","M-staged-PR314","M-staged-PR306","M-staged-PR294","M-staged-PR299","M-staged-PR295","M-staged-PR293","M-staged-PR164","M-staged-PR276","M-staged-PR274","SQUID_3_5_27","M-staged-PR264","M-staged-PR268","M-staged-PR267","M-staged-PR266","M-staged-PR258","M-staged-PR230","M-staged-PR255","M-staged-PR252","M-staged-PR229","M-staged-PR241","M-staged-PR239","M-staged-PR242","M-staged-PR235","M-staged-PR238","M-staged-PR218","M-staged-PR237","M-staged-PR227","M-staged-PR202","M-staged-PR225","M-staged-PR220","M-staged-PR221","M-staged-PR210","M-staged-PR209","M-staged-PR208","M-staged-PR198","M-staged-PR206","M-staged-PR182","M-staged-PR195","M-staged-PR199","M-staged-PR200","M-staged-PR196","M-staged-PR193","M-staged-PR181","M-staged-PR189","M-staged-PR176","M-staged-PR186","M-staged-PR179","M-staged-PR170","M-staged-PR161","SQUID_4_0_16","SQUID_4_0_15","SQUID_4_0_14","SQUID_4_0_13","SQUID_4_0_12","SQUID_4_0_11","SQUID_4_0_10","SQUID_4_0_9","SQUID_4_0_8","SQUID_4_0_7","SQUID_4_0_6","SQUID_4_0_5","SQUID_4_0_4","SQUID_4_0_3","SQUID_4_0_2","SQUID_4_0_1","take00","SQUID_3_0_RC1","SQUID_3_0_PRE7","SQUID_3_0_PRE6","SQUID_3_0_PRE5","SQUID_3_0_PRE4","SQUID_3_0_PRE3","SQUID_3_0_PRE2","SQUID_3_0_PRE1","HISTORIC_RELEASES"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-33526.json","vanir_signatures_modified":"2026-08-12T15:33:24Z","vanir_signatures":[{"digest":{"line_hashes":["73291067842458533164972804911244939871","289434267660738907646178562670084950542","161410907837101138192443052047182141846","288951295780996692180570840948384752569"],"threshold":0.9},"id":"CVE-2026-33526-85b6743e","signature_type":"Line","signature_version":"v1","source":"https://github.com/squid-cache/squid/commit/8a7d42f9d44befb8fcbbb619505587c8de6a1e91","target":{"file":"src/icp_v2.cc"},"deprecated":false},{"id":"CVE-2026-33526-d849cb7b","signature_type":"Function","signature_version":"v1","source":"https://github.com/squid-cache/squid/commit/8a7d42f9d44befb8fcbbb619505587c8de6a1e91","target":{"file":"src/icp_v2.cc","function":"icpGetRequest"},"deprecated":false,"digest":{"length":489,"function_hash":"77918609118482961262740620302725334546"}}]}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H"}]}