{"id":"CVE-2026-56817","title":"io.netty/netty-codec-xml: Netty: Information disclosure via XML External Entity (XXE) vulnerability (CVE-2026-56817)","summary":"A flaw was found in Netty, a network application framework. A remote attacker could exploit this vulnerability by sending specially crafted XML data containing a DOCTYPE declaration to a vulnerable XmlDecoder within the Netty channel pipel…","severity":"high","cvss":7.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N","cvssSource":"vendor","cwe":"CWE-611","vendor":"Red Hat","product":"Red Hat JBoss Enterprise Application Platform 7","affected":["jboss_enterprise_application_platform 7","single_sign_on 7","data_grid 8.6.3","build_of_apache_camel_4_18_3_for_spring_boot 3.5.16"],"patched":["data_grid 8.6.3","build_of_apache_camel_4_18_3_for_spring_boot 3.5.16"],"published":"2026-07-21","updated":"2026-09-21","sourceUpdated":"2026-09-21T16:20:17+00:00","source":"CSAF","sourceUrl":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-56817.json","references":[{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-56817.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-56817"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2505975"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-56817"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-56817"},{"url":"https://github.com/netty/netty/commit/5b68c61f37aa4a3045cba624cbea239655c9003b"},{"url":"https://github.com/netty/netty/commit/bb2ff68a1fb71cb4b0eb9a9e17b66c52aff680c6"},{"url":"https://github.com/netty/netty/releases/tag/netty-4.1.136.Final"},{"url":"https://github.com/netty/netty/releases/tag/netty-4.2.16.Final"},{"url":"https://github.com/netty/netty/security/advisories/GHSA-4qhr-g3c6-fcfx"},{"url":"https://access.redhat.com/errata/RHSA-2026:69296"},{"url":"https://access.redhat.com/errata/RHSA-2026:54622"},{"url":"https://github.com/advisories/GHSA-4qhr-g3c6-fcfx"}],"tags":["csaf","vex","red-hat","ghsa","maven"],"epss":0.00694,"epssPercentile":0.50847,"aliases":["GHSA-4qhr-g3c6-fcfx"],"ecosystem":"maven","ingestedAt":"2026-07-22T22:06:57.796Z","slug":"CVE-2026-56817","body":"## Overview\n\nA flaw was found in Netty, a network application framework. A remote attacker could exploit this vulnerability by sending specially crafted XML data containing a DOCTYPE declaration to a vulnerable XmlDecoder within the Netty channel pipeline. This can lead to an XML External Entity (XXE) vulnerability, potentially allowing the attacker to disclose sensitive information from the system.\n\n## Vendor advisories\n\n- **RHSA-2026:69296** · Red Hat · fixed in: Red Hat Data Grid 8.6.3 · released 2026-09-21 · [advisory](https://access.redhat.com/errata/RHSA-2026:69296)\n- **RHSA-2026:54622** · Red Hat · fixed in: Red Hat build of Apache Camel 4.18.3 for Spring Boot 3.5.16 · released 2026-08-13 · [advisory](https://access.redhat.com/errata/RHSA-2026:54622)\n- **Red Hat VEX** · Important · affected: Red Hat JBoss Enterprise Application Platform 7, Red Hat Single Sign-On 7 · no fix planned: Red Hat JBoss Enterprise Application Platform 7, Red Hat Single Sign-On 7 · updated 2026-09-21 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-56817.json)\n\n**io.netty/netty-codec-xml: Netty: Information disclosure via XML External Entity (XXE) vulnerability** — rated Important by Red Hat. Released 2026-07-21, updated 2026-09-21.\n\nAffected:\n\n- Red Hat JBoss Enterprise Application Platform 7\n- Red Hat Single Sign-On 7\n\nFixed:\n\n- Red Hat Data Grid 8.6.3\n- Red Hat build of Apache Camel 4.18.3 for Spring Boot 3.5.16\n\nNo fix planned:\n\n- Red Hat JBoss Enterprise Application Platform 7\n- Red Hat Single Sign-On 7\n\nNot affected:\n\n- Red Hat JBoss Enterprise Application Platform Expansion Pack\n\n## Remediation\n\nBefore applying this update, make sure all previously released errata relevant to your system have been applied.\n\nFor details on how to apply this update, refer to: https://access.redhat.com/articles/11258 https://access.redhat.com/errata/RHSA-2026:69296\nBefore applying this update, make sure all previously released errata\nrelevant to your system have been applied.\n\nFor details on how to apply this update, refer to:\n\nhttps://access.redhat.com/articles/11258 https://access.redhat.com/errata/RHSA-2026:54622\n\nWorkarounds / mitigations:\n\n- Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.\n\n## Package advisory (CVE-2026-56817)\n\nAffected packages:\n\n- `io.netty:netty-codec-xml >= 4.2.0.Final, <= 4.2.15.Final`\n- `io.netty:netty-codec-xml >= 4.1.0.Final, <= 4.1.135.Final`\n\nPatched in:\n\n- `io.netty:netty-codec-xml 4.2.16.Final`\n- `io.netty:netty-codec-xml 4.1.136.Final`\n\nSource: https://github.com/advisories/GHSA-4qhr-g3c6-fcfx","depth":"twilight","depthScore":41,"depthScoreParts":{"impact":41.3,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[{"seq":208567,"id":"CVE-2026-56817","ts":1790009097026,"field":"cvss","old":null,"new":"7.5"}]}