CVE-2026-33526

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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"}}]}}

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"source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:a:squid-cache:squid:*:*:*:*:*:*:*:*", "matchCriteriaId": "9F62FE66-3319-4718-BD42-B374264D81E8", "versionEndExcluding": "7.5", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "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."}, {"lang": "es", "value": "Squid es un proxy de almacenamiento en cach\u00e9 para la Web. Antes de la versi\u00f3n 7.5, debido a un uso despu\u00e9s de liberaci\u00f3n (Use-After-Free) en el heap, Squid es vulnerable a denegaci\u00f3n de servicio al manejar tr\u00e1fico ICP. Este problema permite a un atacante remoto realizar un ataque de denegaci\u00f3n de servicio fiable y repetible contra el servicio Squid utilizando el protocolo ICP. Este ataque se limita a implementaciones de Squid que habilitan expl\u00edcitamente el soporte ICP (es decir, configuran un 'icp_port' distinto de cero). Este problema _no puede_ mitigarse denegando consultas ICP utilizando reglas de 'icp_access'. La versi\u00f3n 7.5 contiene un parche."}], "id": "CVE-2026-33526", "lastModified": "2026-07-15T02:20:14.400", "metrics": {"cvssMetricV31": [{"cvssData": {"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"}, "exploitabilityScore": 3.9, "impactScore": 3.6, "source": "nvd@nist.gov", "type": "Primary"}, {"cvssData": {"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"}, "exploitabilityScore": 3.9, 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{"bugzilla": {"description": "squid: Squid: Denial of Service via heap Use-After-Free vulnerability in ICP handling", "id": "2451574", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2451574"}, "csaw": false, "cvss3": {"cvss3_base_score": "7.5", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "status": "draft"}, "cwe": "CWE-825", "details": ["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."], "mitigation": {"lang": "en:us", "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."}, "name": "CVE-2026-33526", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Affected", "package_name": "squid", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Out of support scope", "package_name": "squid", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Out of support scope", "package_name": "squid34", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Affected", "package_name": "squid", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Affected", "package_name": "squid:4/squid", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "squid", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2026-03-26T00:16:12Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-33526\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-33526\nhttp://www.openwall.com/lists/oss-security/2026/03/25/2\nhttps://github.com/squid-cache/squid/commit/8a7d42f9d44befb8fcbbb619505587c8de6a1e91\nhttps://github.com/squid-cache/squid/security/advisories/GHSA-hpfx-h48q-gvwg"], "statement": "Important: A heap Use-After-Free vulnerability in Squid's ICP handling can lead to a denial of service. This flaw affects Red Hat products where the Squid proxy is configured to explicitly enable Internet Cache Protocol (ICP) support by setting a non-zero `icp_port`. Deployments with default configurations, where ICP is typically disabled, are not affected.", "threat_severity": "Important"}

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