{"attribution":"This product uses data from the NVD API but is not endorsed or certified by the NVD.","cve":{"id":"CVE-2026-56819","sourceIdentifier":"security-advisories@github.com","published":"2026-07-21T23:17:52.263","lastModified":"2026-07-30T14:46:35.563","vulnStatus":"Analyzed","cveTags":[],"descriptions":[{"lang":"en","value":"Netty is a network application framework for development of protocol servers and clients. In versions 4.2.0.Final through 4.2.15.Final and 4.1.0.Final through 4.1.135.Final, a remote unauthenticated peer can leak one direct `ByteBuf` per HTTP/2 `DATA` frame in applications that enable HTTP/2 content decompression via `DelegatingDecompressorFrameListener`. When a `DATA` frame is processed for a stream whose decompressor has already been closed, `Http2Decompressor.decompress(...)` calls `decompressor.writeInbound(data.retain())` and does not release the retained buffer on the error path, eventually exhausting direct memory and crashing the JVM. This issue is fixed in versions 4.1.136.Final and 4.2.16.Final."}],"affected":[{"source":"security-advisories@github.com","affectedData":[{"vendor":"netty","product":"netty","versions":[{"version":"\u003e= 4.2.0.Final, \u003c 4.2.16.Final","status":"affected"},{"version":"\u003e= 4.1.0.Final, \u003c 4.1.136.Final","status":"affected"}]}]}],"metrics":{"cvssMetricV31":[{"source":"security-advisories@github.com","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","baseScore":7.5,"baseSeverity":"HIGH","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"HIGH"},"exploitabilityScore":3.9,"impactScore":3.6}],"ssvcV203":[{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","ssvcData":{"timestamp":"2026-07-23T13:55:20.959839Z","id":"CVE-2026-56819","options":[{"exploitation":"poc"},{"automatable":"yes"},{"technicalImpact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}]},"weaknesses":[{"source":"security-advisories@github.com","type":"Secondary","description":[{"lang":"en","value":"CWE-400"},{"lang":"en","value":"CWE-401"}]}],"configurations":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:netty:netty:*:*:*:*:*:*:*:*","versionStartIncluding":"4.1.0","versionEndExcluding":"4.1.136","matchCriteriaId":"09BEF8E6-BE3C-4815-AAAA-2AFFCDE2D786"},{"vulnerable":true,"criteria":"cpe:2.3:a:netty:netty:*:*:*:*:*:*:*:*","versionStartIncluding":"4.2.0","versionEndExcluding":"4.2.16","matchCriteriaId":"4DE4BC35-4405-49B5-A2A8-A700C7F63C8B"}]}]}],"references":[{"url":"https://github.com/netty/netty/commit/5b68c61f37aa4a3045cba624cbea239655c9003b","source":"security-advisories@github.com","tags":["Patch"]},{"url":"https://github.com/netty/netty/commit/bb2ff68a1fb71cb4b0eb9a9e17b66c52aff680c6","source":"security-advisories@github.com","tags":["Patch"]},{"url":"https://github.com/netty/netty/releases/tag/netty-4.1.136.Final","source":"security-advisories@github.com","tags":["Release Notes"]},{"url":"https://github.com/netty/netty/releases/tag/netty-4.2.16.Final","source":"security-advisories@github.com","tags":["Release Notes"]},{"url":"https://github.com/netty/netty/security/advisories/GHSA-93wv-jw9v-4972","source":"security-advisories@github.com","tags":["Exploit","Vendor Advisory"]},{"url":"https://github.com/netty/netty/security/advisories/GHSA-93wv-jw9v-4972","source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","tags":["Exploit","Vendor Advisory"]}]}}