{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-33526", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "state": "PUBLISHED", "assignerShortName": "GitHub_M", "dateReserved": "2026-03-20T18:05:11.830Z", "datePublished": "2026-03-26T00:16:12.195Z", "dateUpdated": "2026-07-15T01:06:16.373Z" }, "containers": { "cna": { "title": "Squid vulnerable to Denial of Service in ICP Request handling", "problemTypes": [ { "descriptions": [ { "cweId": "CWE-416", "lang": "en", "description": "CWE-416: Use After Free", "type": "CWE" } ] }, { "descriptions": [ { "cweId": "CWE-826", "lang": "en", "description": "CWE-826: Premature Release of Resource During Expected Lifetime", "type": "CWE" } ] } ], "metrics": [ { "cvssV4_0": { "attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "userInteraction": "NONE", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "NONE", "vulnAvailabilityImpact": "HIGH", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "HIGH", "baseScore": 9.2, "baseSeverity": "CRITICAL", "vectorString": "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", "version": "4.0" } } ], "references": [ { "name": "https://github.com/squid-cache/squid/security/advisories/GHSA-hpfx-h48q-gvwg", "tags": [ "x_refsource_CONFIRM" ], "url": "https://github.com/squid-cache/squid/security/advisories/GHSA-hpfx-h48q-gvwg" }, { "name": "https://github.com/squid-cache/squid/commit/8a7d42f9d44befb8fcbbb619505587c8de6a1e91", "tags": [ "x_refsource_MISC" ], "url": "https://github.com/squid-cache/squid/commit/8a7d42f9d44befb8fcbbb619505587c8de6a1e91" } ], "affected": [ { "vendor": "squid-cache", "product": "squid", "versions": [ { "version": "< 7.5", "status": "affected" } ] } ], "providerMetadata": { "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-03-26T00:16:12.195Z" }, "descriptions": [ { "lang": "en", "value": "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." } ], "source": { "advisory": "GHSA-hpfx-h48q-gvwg", "discovery": "UNKNOWN" } }, "adp": [ { "title": "CVE Program Container", "references": [ { "url": "http://www.openwall.com/lists/oss-security/2026/03/25/2" } ], "providerMetadata": { "orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2026-03-26T00:24:58.639Z" } }, { "metrics": [ { "other": { "type": "ssvc", "content": { "timestamp": "2026-03-26T18:20:32.942486Z", "id": "CVE-2026-33526", "options": [ { "Exploitation": "none" }, { "Automatable": "yes" }, { "Technical Impact": "partial" } ], "role": "CISA Coordinator", "version": "2.0.3" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-03-26T18:20:40.309Z" } }, { "affected": [ { "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": [ "cpe:/o:redhat:enterprise_linux:10.1" ], 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"versionType": "rpm" } ] }, { "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": [ "cpe:/a:redhat:enterprise_linux:8" ], "defaultStatus": "affected", "packageName": "squid:4", "product": "Red Hat Enterprise Linux 8", "vendor": "Red Hat", "versions": [ { "lessThan": "*", "status": "unaffected", "version": "8100020260408092701.489197e6", "versionType": "rpm" } ] }, { "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": [ "cpe:/a:redhat:rhel_aus:8.4" ], "defaultStatus": "affected", "packageName": "squid:4", "product": "Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support", "vendor": "Red Hat", "versions": [ { "lessThan": "*", "status": "unaffected", "version": "8040020260514123440.522a0ee4", "versionType": "rpm" } ] }, { "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": [ "cpe:/a:redhat:rhel_eus_long_life:8.4" ], "defaultStatus": "affected", "packageName": "squid:4", "product": "Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On", "vendor": "Red Hat", "versions": [ { "lessThan": "*", "status": "unaffected", "version": "8040020260514123440.522a0ee4", "versionType": "rpm" } ] }, { "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": [ "cpe:/a:redhat:rhel_aus:8.6" ], "defaultStatus": "affected", "packageName": "squid:4", "product": "Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support", "vendor": "Red Hat", "versions": [ { "lessThan": "*", "status": "unaffected", "version": "8060020260518090356.ad008a3a", "versionType": "rpm" } ] }, { "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": [ "cpe:/a:redhat:rhel_tus:8.6" ], "defaultStatus": "affected", "packageName": "squid:4", "product": "Red Hat Enterprise Linux 8.6 Telecommunications Update Service", "vendor": "Red Hat", "versions": [ { "lessThan": "*", "status": "unaffected", "version": "8060020260518090356.ad008a3a", "versionType": "rpm" } ] }, { "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": [ "cpe:/a:redhat:rhel_e4s:8.6" ], "defaultStatus": "affected", "packageName": "squid:4", "product": "Red Hat Enterprise Linux 8.6 Update Services for SAP Solutions", "vendor": "Red Hat", "versions": [ { "lessThan": "*", "status": "unaffected", "version": "8060020260518090356.ad008a3a", "versionType": "rpm" } ] }, { "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": [ "cpe:/a:redhat:rhel_tus:8.8" ], "defaultStatus": "affected", "packageName": "squid:4", "product": "Red Hat Enterprise Linux 8.8 Telecommunications Update Service", "vendor": "Red Hat", "versions": [ { "lessThan": "*", "status": "unaffected", "version": "8080020260514105733.63b34585", "versionType": "rpm" } ] }, { "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": [ "cpe:/a:redhat:rhel_e4s:8.8" ], "defaultStatus": "affected", "packageName": "squid:4", "product": "Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions", "vendor": "Red Hat", "versions": [ { "lessThan": "*", "status": "unaffected", "version": "8080020260514105733.63b34585", "versionType": "rpm" } ] }, { "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": [ "cpe:/a:redhat:enterprise_linux:9" ], "defaultStatus": "affected", "packageName": "squid", "product": "Red Hat Enterprise Linux 9", "vendor": "Red Hat", "versions": [ { "lessThan": "*", "status": "unaffected", "version": "7:5.5-22.el9_7.4", "versionType": "rpm" } ] }, { "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": [ "cpe:/a:redhat:rhel_e4s:9.0" ], "defaultStatus": "affected", "packageName": "squid", "product": "Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions", "vendor": "Red Hat", "versions": [ { "lessThan": "*", "status": "unaffected", "version": "7:5.2-1.el9_0.10", "versionType": "rpm" } ] }, { "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": [ "cpe:/a:redhat:rhel_e4s:9.2" ], "defaultStatus": "affected", "packageName": "squid", "product": "Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions", "vendor": "Red Hat", "versions": [ { "lessThan": "*", "status": "unaffected", "version": "7:5.5-5.el9_2.11", "versionType": "rpm" } ] }, { "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": [ "cpe:/a:redhat:rhel_eus:9.4" ], "defaultStatus": "affected", "packageName": "squid", "product": "Red Hat Enterprise Linux 9.4 Extended Update Support", "vendor": "Red Hat", "versions": [ { "lessThan": "*", "status": "unaffected", "version": "7:5.5-13.el9_4.5", "versionType": "rpm" } ] }, { "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": [ "cpe:/a:redhat:rhel_eus:9.6" ], "defaultStatus": "affected", "packageName": "squid", "product": "Red Hat Enterprise Linux 9.6 Extended Update Support", "vendor": "Red Hat", "versions": [ { "lessThan": "*", "status": "unaffected", "version": "7:5.5-19.el9_6.3", "versionType": "rpm" } ] }, { "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": [ "cpe:/o:redhat:enterprise_linux:6" ], "defaultStatus": "unknown", "packageName": "squid", "product": "Red Hat Enterprise Linux 6", "vendor": "Red Hat" }, { "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": [ "cpe:/o:redhat:enterprise_linux:6" ], "defaultStatus": "unknown", "packageName": "squid34", "product": "Red Hat Enterprise Linux 6", "vendor": "Red Hat" } ], "datePublic": "2026-03-26T00:16:12.195Z", "descriptions": [ { "lang": "en", "value": "A flaw was found in Squid. A remote attacker can exploit a heap Use-After-Free vulnerability when handling ICP (Internet Cache Protocol) traffic. This allows them to perform a reliable and repeatable Denial of Service (DoS) attack, making the Squid service unavailable. This attack is limited to deployments where ICP support is explicitly enabled." } ], "metrics": [ { "other": { "content": { "namespace": "https://access.redhat.com/security/updates/classification/", "value": "Important" }, "type": "Red Hat severity rating" } }, { "cvssV3_1": { "attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 7.5, "baseSeverity": "HIGH", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "version": "3.1" }, "format": "CVSS" } ], "problemTypes": [ { "descriptions": [ { "cweId": "CWE-825", "description": "Expired Pointer Dereference", "lang": "en", "type": "CWE" } ] } ], "references": [ { "tags": [ "vdb-entry", "x_refsource_REDHAT" ], "url": "https://access.redhat.com/security/cve/CVE-2026-33526" }, { "name": "RHBZ#2451574", "tags": [ "issue-tracking", "x_refsource_REDHAT" ], "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2451574" }, { "tags": [ "x_sadp-csaf-vex" ], "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-33526.json" }, { "tags": [ "vendor-advisory", "x_refsource_REDHAT" ], "url": "https://access.redhat.com/errata/RHSA-2026:8880" }, { "tags": [ "vendor-advisory", "x_refsource_REDHAT" ], "url": "https://access.redhat.com/errata/RHSA-2026:11901" }, { "tags": [ "vendor-advisory", "x_refsource_REDHAT" ], "url": "https://access.redhat.com/errata/RHSA-2026:8119" }, { "tags": [ "vendor-advisory", "x_refsource_REDHAT" ], "url": "https://access.redhat.com/errata/RHSA-2026:8317" }, { "tags": [ "vendor-advisory", "x_refsource_REDHAT" ], "url": "https://access.redhat.com/errata/RHSA-2026:20564" }, { "tags": [ "vendor-advisory", "x_refsource_REDHAT" ], "url": "https://access.redhat.com/errata/RHSA-2026:20565" }, { "tags": [ "vendor-advisory", "x_refsource_REDHAT" ], "url": "https://access.redhat.com/errata/RHSA-2026:20580" }, { "tags": [ "vendor-advisory", "x_refsource_REDHAT" ], "url": "https://access.redhat.com/errata/RHSA-2026:10256" }, { "tags": [ "vendor-advisory", "x_refsource_REDHAT" ], "url": "https://access.redhat.com/errata/RHSA-2026:10257" }, { "tags": [ "vendor-advisory", "x_refsource_REDHAT" ], "url": "https://access.redhat.com/errata/RHSA-2026:10255" }, { "tags": [ "vendor-advisory", "x_refsource_REDHAT" ], "url": "https://access.redhat.com/errata/RHSA-2026:9220" }, { "tags": [ "vendor-advisory", "x_refsource_REDHAT" ], "url": "https://access.redhat.com/errata/RHSA-2026:6301" } ], "solutions": [ { "lang": "en", "value": "RHSA-2026:8880: Red Hat Enterprise Linux Server (v. 7 ELS)" }, { "lang": "en", "value": "RHSA-2026:11901: Red Hat Enterprise Linux AppStream EUS (v. 10.0)" }, { "lang": "en", "value": "RHSA-2026:8119: Red Hat Enterprise Linux AppStream (v. 10)" }, { "lang": "en", "value": "RHSA-2026:8317: Red Hat Enterprise Linux AppStream (v. 8)" }, { "lang": "en", "value": "RHSA-2026:20564: Red Hat Enterprise Linux AppStream AUS (v.8.4), Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4)" }, { "lang": "en", "value": "RHSA-2026:20565: Red Hat Enterprise Linux AppStream AUS (v.8.6), Red Hat Enterprise Linux AppStream E4S (v.8.6), Red Hat Enterprise Linux AppStream TUS (v.8.6)" }, { "lang": "en", "value": "RHSA-2026:20580: Red Hat Enterprise Linux AppStream E4S (v.8.8), Red Hat Enterprise Linux AppStream TUS (v.8.8)" }, { "lang": "en", "value": "RHSA-2026:10256: Red Hat Enterprise Linux AppStream E4S (v.9.0)" }, { "lang": "en", "value": "RHSA-2026:10257: Red Hat Enterprise Linux AppStream E4S (v.9.2)" }, { "lang": "en", "value": "RHSA-2026:10255: Red Hat Enterprise Linux AppStream EUS (v.9.4)" }, { "lang": "en", "value": "RHSA-2026:9220: Red Hat Enterprise Linux AppStream EUS (v.9.6)" }, { "lang": "en", "value": "RHSA-2026:6301: Red Hat Enterprise Linux AppStream (v. 9)" } ], "timeline": [ { "lang": "en", "time": "2026-03-26T01:01:16.233Z", "value": "Reported to Red Hat." }, { "lang": "en", "time": "2026-03-26T00:16:12.195Z", "value": "Made public." } ], "title": "squid: Squid: Denial of Service via heap Use-After-Free vulnerability in ICP handling", "workarounds": [ { "lang": "en", "value": "To mitigate this issue, disable ICP support in Squid by ensuring that `icp_port` is set to `0` in the `squid.conf` configuration file. This will prevent Squid from processing ICP traffic and eliminate the attack vector. After modifying the configuration, the Squid service must be restarted for the changes to take effect." } ], "x_adpType": "supplier", "x_generator": { "engine": "sadp-cli 1.0.0" }, "providerMetadata": { "orgId": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c", "shortName": "redhat-SADP", "dateUpdated": "2026-07-15T01:06:16.373Z" } } ] } }