Find a vulnerability

{
  "affected": [
    {
      "package": {
        "ecosystem": "Maven",
        "name": "io.netty:netty-handler-ssl-ocsp"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "4.2.0.Final"
            },
            {
              "fixed": "4.2.16.Final"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Maven",
        "name": "io.netty:netty-handler-ssl-ocsp"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "4.1.136.Final"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-56821"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-299"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-07-22T21:46:39Z",
    "nvd_published_at": null,
    "severity": "HIGH"
  },
  "details": "### Summary\n`OcspServerCertificateValidator` flags an out-of-date OCSP response but does not stop processing it, so an expired GOOD response is still reported as `VALID`, letting an on-path attacker replay a stale GOOD response to bypass revocation of a since-revoked certificate.\n\n### Details\nIn `io.netty.handler.ssl.ocsp.OcspServerCertificateValidator#userEventTriggered` the freshness check has no `return`, so execution falls through and a `VALID` `OcspValidationEvent` is still fired:\n\n```java\n                        if (!(current.after(response.getThisUpdate()) \u0026\u0026\n                                current.before(response.getNextUpdate()))) {\n                            ctx.fireExceptionCaught(new IllegalStateException(\"OCSP Response is out-of-date\"));\n                        }\n```\n\nNonce validation is optional and off by default, so freshness is the only replay defense \u2014 and it is not enforced. Additionally `getNextUpdate()` may be `null`, making `current.before(null)` throw `NullPointerException`.\n\nhttps://datatracker.ietf.org/doc/html/rfc6960#section-3.2\n\n```\n   5. The time at which the status being indicated is known to be\n      correct (thisUpdate) is sufficiently recent;\n\n   6. When available, the time at or before which newer information will\n      be available about the status of the certificate (nextUpdate) is\n      greater than the current time.\n```\n\n### PoC\n\nAdd the test below to `io.netty.handler.ssl.ocsp.OcspServerCertificateValidatorTest`\n\n```java\n    @Test\n    void staleOcspResponseIsRejected() throws Exception {\n        X509Bundle caRoot = new CertificateBuilder()\n                .algorithm(CertificateBuilder.Algorithm.rsa2048)\n                .subject(\"CN=TrustedRootCA\")\n                .setIsCertificateAuthority(true)\n                .buildSelfSigned();\n\n        GeneralName ocspName = new GeneralName(GeneralName.uniformResourceIdentifier, \"http://localhost/\");\n        AuthorityInformationAccess aia = new AuthorityInformationAccess(\n                new AccessDescription(AccessDescription.id_ad_ocsp, ocspName));\n        X509Bundle targetCert = new CertificateBuilder()\n                .algorithm(CertificateBuilder.Algorithm.rsa2048)\n                .subject(\"CN=TargetServer\")\n                .addExtensionOctetString(\"1.3.6.1.5.5.7.1.1\", false, aia.getEncoded())\n                .buildIssuedBy(caRoot);\n\n        Date past = new Date(System.currentTimeMillis() - TimeUnit.DAYS.toMillis(7));\n        CertificateID certId = new CertificateID(\n                new JcaDigestCalculatorProviderBuilder().build().get(CertificateID.HASH_SHA1),\n                new JcaX509CertificateHolder(caRoot.getCertificate()),\n                targetCert.getCertificate().getSerialNumber());\n        BasicOCSPRespBuilder respBuilder = new BasicOCSPRespBuilder(\n                new RespID(new JcaX509CertificateHolder(caRoot.getCertificate()).getSubject()));\n        respBuilder.addResponse(certId, CertificateStatus.GOOD, past, past);\n        BasicOCSPResp expiredBasicResp = respBuilder.build(\n                new JcaContentSignerBuilder(\"SHA256withRSA\").build(caRoot.getKeyPair().getPrivate()),\n                new X509CertificateHolder[0],\n                past);\n        final byte[] responseEncoded = new OCSPRespBuilder()\n                .build(OCSPRespBuilder.SUCCESSFUL, expiredBasicResp).getEncoded();\n\n        IoTransport defaultTransport = createDefaultTransport();\n        IoTransport mockTransport = IoTransport.create(defaultTransport.eventLoop(), () -\u003e {\n                NioSocketChannel channel = new NioSocketChannel();\n                channel.pipeline().addFirst(new ChannelOutboundHandlerAdapter() {\n                    @Override\n                    public void connect(ChannelHandlerContext ctx, SocketAddress remoteAddress,\n                                        SocketAddress localAddress, ChannelPromise promise) {\n                        promise.setSuccess();\n                        ctx.executor().execute(() -\u003e {\n                            ctx.pipeline().fireChannelActive();\n                            DefaultFullHttpResponse httpResponse = new DefaultFullHttpResponse(\n                                    HttpVersion.HTTP_1_1, HttpResponseStatus.OK,\n                                    Unpooled.wrappedBuffer(responseEncoded));\n                            httpResponse.headers().set(HttpHeaderNames.CONTENT_TYPE, \"application/ocsp-response\");\n                            httpResponse.headers().set(HttpHeaderNames.CONTENT_LENGTH,\n                                    httpResponse.content().readableBytes());\n                            ctx.pipeline().fireChannelRead(httpResponse);\n                        });\n                    }\n                });\n                return channel;\n            }, defaultTransport.datagramChannel());\n\n            SslContext serverSslCtx = SslContextBuilder\n                    .forServer(targetCert.getKeyPair().getPrivate(),\n                            targetCert.getCertificate(), caRoot.getCertificate())\n                    .build();\n            Channel serverChannel = new ServerBootstrap()\n                    .group(defaultTransport.eventLoop())\n                    .channel(NioServerSocketChannel.class)\n                    .childHandler(new ChannelInitializer\u003cSocketChannel\u003e() {\n                        @Override\n                        protected void initChannel(SocketChannel ch) {\n                            ch.pipeline().addLast(serverSslCtx.newHandler(ch.alloc()));\n                        }\n                    })\n                    .bind(0).sync().channel();\n\n            int serverPort = ((InetSocketAddress) serverChannel.localAddress()).getPort();\n\n            AtomicBoolean validEventFired = new AtomicBoolean();\n            AtomicReference\u003cThrowable\u003e caughtException = new AtomicReference\u003c\u003e();\n            CountDownLatch latch = new CountDownLatch(1);\n\n            DnsNameResolver resolver = OcspServerCertificateValidator.createDefaultResolver(mockTransport);\n            SslContext clientSslCtx = SslContextBuilder.forClient()\n                    .trustManager(InsecureTrustManagerFactory.INSTANCE)\n                    .build();\n            new Bootstrap()\n                    .group(defaultTransport.eventLoop())\n                    .channel(NioSocketChannel.class)\n                    .handler(new ChannelInitializer\u003cSocketChannel\u003e() {\n                        @Override\n                        protected void initChannel(SocketChannel ch) {\n                            ch.pipeline().addLast(clientSslCtx.newHandler(ch.alloc(), \"127.0.0.1\", serverPort));\n                            ch.pipeline().addLast(\n                                    new OcspServerCertificateValidator(true, false, mockTransport, resolver));\n                            ch.pipeline().addLast(new ChannelInboundHandlerAdapter() {\n                                @Override\n                                public void userEventTriggered(ChannelHandlerContext ctx, Object evt) {\n                                    if (evt instanceof OcspValidationEvent \u0026\u0026\n                                            ((OcspValidationEvent) evt).response().status() ==\n                                                    OcspResponse.Status.VALID) {\n                                        validEventFired.set(true);\n                                    }\n                                    ctx.fireUserEventTriggered(evt);\n                                }\n\n                                @Override\n                                public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {\n                                    caughtException.compareAndSet(null, cause);\n                                    ctx.channel().close();\n                                    latch.countDown();\n                                }\n                            });\n                        }\n                    })\n                    .connect(\"127.0.0.1\", serverPort).sync();\n\n            assertTrue(latch.await(5, TimeUnit.SECONDS));\n            assertFalse(validEventFired.get(),\n                    \"OcspValidationEvent(VALID) must not be emitted for a stale OCSP response\");\n            assertNotNull(caughtException.get());\n            assertInstanceOf(IllegalStateException.class, caughtException.get());\n\n            serverChannel.close().sync();\n            resolver.close();\n    }\n```\n### Impact\nCertificate revocation bypass via replay of an expired OCSP response. Any application using `OcspServerCertificateValidator` is affected; a revoked certificate can be accepted.",
  "id": "GHSA-g7hg-vrcf-mvmr",
  "modified": "2026-07-22T21:46:39Z",
  "published": "2026-07-22T21:46:39Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/netty/netty/security/advisories/GHSA-g7hg-vrcf-mvmr"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/netty/netty"
    },
    {
      "type": "WEB",
      "url": "https://github.com/netty/netty/releases/tag/netty-4.1.136.Final"
    },
    {
      "type": "WEB",
      "url": "https://github.com/netty/netty/releases/tag/netty-4.2.16.Final"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Netty: Out-of-date OCSP Responses Accepted by OcspServerCertificateValidator"
}

{
  "document": {
    "aggregate_severity": {
      "text": "hoch"
    },
    "category": "csaf_base",
    "csaf_version": "2.0",
    "distribution": {
      "tlp": {
        "label": "WHITE",
        "url": "https://www.first.org/tlp/"
      }
    },
    "lang": "de-DE",
    "notes": [
      {
        "category": "legal_disclaimer",
        "text": "Das BSI ist als Anbieter f\u00fcr die eigenen, zur Nutzung bereitgestellten Inhalte nach den allgemeinen Gesetzen verantwortlich. Nutzerinnen und Nutzer sind jedoch daf\u00fcr verantwortlich, die Verwendung und/oder die Umsetzung der mit den Inhalten bereitgestellten Informationen sorgf\u00e4ltig im Einzelfall zu pr\u00fcfen."
      },
      {
        "category": "description",
        "text": "Netty ist ein asynchrones, ereignisgesteuertes Netzwerk-Anwendungs-Framework f\u00fcr die schnelle Entwicklung von wartbaren, hochleistungsf\u00e4higen Protokollservern und -clients.",
        "title": "Produktbeschreibung"
      },
      {
        "category": "summary",
        "text": "Ein Angreifer kann mehrere Schwachstellen in Netty ausnutzen, um Sicherheitspr\u00fcfungen zu umgehen, Anfragen oder Header zu manipulieren, Zertifikatspr\u00fcfungen zu unterlaufen sowie einen Denial of Service zu verursachen.",
        "title": "Angriff"
      },
      {
        "category": "general",
        "text": "- Linux\n- UNIX",
        "title": "Betroffene Betriebssysteme"
      }
    ],
    "publisher": {
      "category": "other",
      "contact_details": "csaf-provider@cert-bund.de",
      "name": "Bundesamt f\u00fcr Sicherheit in der Informationstechnik",
      "namespace": "https://www.bsi.bund.de"
    },
    "references": [
      {
        "category": "self",
        "summary": "WID-SEC-W-2026-2356 - CSAF Version",
        "url": "https://wid.cert-bund.de/.well-known/csaf/white/2026/wid-sec-w-2026-2356.json"
      },
      {
        "category": "self",
        "summary": "WID-SEC-2026-2356 - Portal Version",
        "url": "https://wid.cert-bund.de/portal/wid/securityadvisory?name=WID-SEC-2026-2356"
      },
      {
        "category": "external",
        "summary": "GitHub Security Advisory GHSA-4qhr-g3c6-fcfx vom 2026-07-14",
        "url": "https://github.com/netty/netty/security/advisories/GHSA-4qhr-g3c6-fcfx"
      },
      {
        "category": "external",
        "summary": "GitHub Security Advisory GHSA-272m-gcwp-mpwg vom 2026-07-14",
        "url": "https://github.com/netty/netty/security/advisories/GHSA-272m-gcwp-mpwg"
      },
      {
        "category": "external",
        "summary": "GitHub Security Advisory GHSA-3g8r-4pfx-jmfh vom 2026-07-14",
        "url": "https://github.com/netty/netty/security/advisories/GHSA-3g8r-4pfx-jmfh"
      },
      {
        "category": "external",
        "summary": "GitHub Security Advisory GHSA-4mp9-239f-g9hg vom 2026-07-14",
        "url": "https://github.com/netty/netty/security/advisories/GHSA-4mp9-239f-g9hg"
      },
      {
        "category": "external",
        "summary": "GitHub Security Advisory GHSA-q4f6-jm68-57ww vom 2026-07-14",
        "url": "https://github.com/netty/netty/security/advisories/GHSA-q4f6-jm68-57ww"
      },
      {
        "category": "external",
        "summary": "GitHub Security Advisory GHSA-c69g-56f8-xwqj vom 2026-07-14",
        "url": "https://github.com/netty/netty/security/advisories/GHSA-c69g-56f8-xwqj"
      },
      {
        "category": "external",
        "summary": "GitHub Security Advisory GHSA-558v-64gr-wgg4 vom 2026-07-14",
        "url": "https://github.com/netty/netty/security/advisories/GHSA-558v-64gr-wgg4"
      },
      {
        "category": "external",
        "summary": "GitHub Security Advisory GHSA-6jqx-86gh-f27w vom 2026-07-14",
        "url": "https://github.com/netty/netty/security/advisories/GHSA-6jqx-86gh-f27w"
      },
      {
        "category": "external",
        "summary": "GitHub Security Advisory GHSA-93wv-jw9v-4972 vom 2026-07-14",
        "url": "https://github.com/netty/netty/security/advisories/GHSA-93wv-jw9v-4972"
      },
      {
        "category": "external",
        "summary": "GitHub Security Advisory GHSA-g7hg-vrcf-mvmr vom 2026-07-14",
        "url": "https://github.com/netty/netty/security/advisories/GHSA-g7hg-vrcf-mvmr"
      },
      {
        "category": "external",
        "summary": "GitHub Security Advisory GHSA-gcjf-9mgh-3p7g vom 2026-07-14",
        "url": "https://github.com/netty/netty/security/advisories/GHSA-gcjf-9mgh-3p7g"
      },
      {
        "category": "external",
        "summary": "GitHub Security Advisory GHSA-hpcc-26xq-25fv vom 2026-07-14",
        "url": "https://github.com/netty/netty/security/advisories/GHSA-hpcc-26xq-25fv"
      },
      {
        "category": "external",
        "summary": "GitHub Security Advisory GHSA-jppx-w49h-x2qq vom 2026-07-14",
        "url": "https://github.com/netty/netty/security/advisories/GHSA-jppx-w49h-x2qq"
      },
      {
        "category": "external",
        "summary": "GitHub Security Advisory GHSA-mvh2-crg5-v77c vom 2026-07-14",
        "url": "https://github.com/netty/netty/security/advisories/GHSA-mvh2-crg5-v77c"
      },
      {
        "category": "external",
        "summary": "GitHub Security Advisory GHSA-q6cq-mhr2-jmr5 vom 2026-07-14",
        "url": "https://github.com/netty/netty/security/advisories/GHSA-q6cq-mhr2-jmr5"
      },
      {
        "category": "external",
        "summary": "GitHub Security Advisory GHSA-vhch-2wf3-m8rp vom 2026-07-14",
        "url": "https://github.com/netty/netty/security/advisories/GHSA-vhch-2wf3-m8rp"
      },
      {
        "category": "external",
        "summary": "GitHub Security Advisory GHSA-wc96-39fc-566f vom 2026-07-14",
        "url": "https://github.com/netty/netty/security/advisories/GHSA-wc96-39fc-566f"
      }
    ],
    "source_lang": "en-US",
    "title": "Netty: Mehrere Schwachstellen",
    "tracking": {
      "current_release_date": "2026-07-21T22:00:00.000+00:00",
      "generator": {
        "date": "2026-07-22T09:20:42.612+00:00",
        "engine": {
          "name": "BSI-WID",
          "version": "1.6.0"
        }
      },
      "id": "WID-SEC-W-2026-2356",
      "initial_release_date": "2026-07-14T22:00:00.000+00:00",
      "revision_history": [
        {
          "date": "2026-07-14T22:00:00.000+00:00",
          "number": "1",
          "summary": "Initiale Fassung"
        },
        {
          "date": "2026-07-19T22:00:00.000+00:00",
          "number": "2",
          "summary": "Referenz(en) aufgenommen: EUVD-2026-45316"
        },
        {
          "date": "2026-07-20T22:00:00.000+00:00",
          "number": "3",
          "summary": "Referenz(en) aufgenommen: EUVD-2026-46133, EUVD-2026-46132"
        },
        {
          "date": "2026-07-21T22:00:00.000+00:00",
          "number": "4",
          "summary": "Referenz(en) aufgenommen: EUVD-2026-46452, EUVD-2026-46438, EUVD-2026-47564, EUVD-2026-47579, EUVD-2026-47582, EUVD-2026-47581"
        }
      ],
      "status": "final",
      "version": "4"
    }
  },
  "product_tree": {
    "branches": [
      {
        "branches": [
          {
            "branches": [
              {
                "category": "product_version_range",
                "name": "\u003c4.2.16",
                "product": {
                  "name": "Open Source Netty \u003c4.2.16",
                  "product_id": "T056598"
                }
              },
              {
                "category": "product_version",
                "name": "4.2.16",
                "product": {
                  "name": "Open Source Netty 4.2.16",
                  "product_id": "T056598-fixed",
                  "product_identification_helper": {
                    "cpe": "cpe:/a:netty:netty:4.2.16"
                  }
                }
              },
              {
                "category": "product_version_range",
                "name": "\u003c4.1.136",
                "product": {
                  "name": "Open Source Netty \u003c4.1.136",
                  "product_id": "T056599"
                }
              },
              {
                "category": "product_version",
                "name": "4.1.136",
                "product": {
                  "name": "Open Source Netty 4.1.136",
                  "product_id": "T056599-fixed",
                  "product_identification_helper": {
                    "cpe": "cpe:/a:netty:netty:4.1.136"
                  }
                }
              }
            ],
            "category": "product_name",
            "name": "Netty"
          }
        ],
        "category": "vendor",
        "name": "Open Source"
      }
    ]
  },
  "vulnerabilities": [
    {
      "cve": "CVE-2026-44891",
      "product_status": {
        "known_affected": [
          "T056599",
          "T056598"
        ]
      },
      "release_date": "2026-07-14T22:00:00.000+00:00",
      "title": "CVE-2026-44891"
    },
    {
      "cve": "CVE-2026-55831",
      "product_status": {
        "known_affected": [
          "T056599",
          "T056598"
        ]
      },
      "release_date": "2026-07-14T22:00:00.000+00:00",
      "title": "CVE-2026-55831"
    },
    {
      "cve": "CVE-2026-55833",
      "product_status": {
        "known_affected": [
          "T056599",
          "T056598"
        ]
      },
      "release_date": "2026-07-14T22:00:00.000+00:00",
      "title": "CVE-2026-55833"
    },
    {
      "cve": "CVE-2026-55851",
      "product_status": {
        "known_affected": [
          "T056599",
          "T056598"
        ]
      },
      "release_date": "2026-07-14T22:00:00.000+00:00",
      "title": "CVE-2026-55851"
    },
    {
      "cve": "CVE-2026-56745",
      "product_status": {
        "known_affected": [
          "T056599",
          "T056598"
        ]
      },
      "release_date": "2026-07-14T22:00:00.000+00:00",
      "title": "CVE-2026-56745"
    },
    {
      "cve": "CVE-2026-56816",
      "product_status": {
        "known_affected": [
          "T056599",
          "T056598"
        ]
      },
      "release_date": "2026-07-14T22:00:00.000+00:00",
      "title": "CVE-2026-56816"
    },
    {
      "cve": "CVE-2026-56817",
      "product_status": {
        "known_affected": [
          "T056599",
          "T056598"
        ]
      },
      "release_date": "2026-07-14T22:00:00.000+00:00",
      "title": "CVE-2026-56817"
    },
    {
      "cve": "CVE-2026-56819",
      "product_status": {
        "known_affected": [
          "T056599",
          "T056598"
        ]
      },
      "release_date": "2026-07-14T22:00:00.000+00:00",
      "title": "CVE-2026-56819"
    },
    {
      "cve": "CVE-2026-56820",
      "product_status": {
        "known_affected": [
          "T056599",
          "T056598"
        ]
      },
      "release_date": "2026-07-14T22:00:00.000+00:00",
      "title": "CVE-2026-56820"
    },
    {
      "cve": "CVE-2026-56821",
      "product_status": {
        "known_affected": [
          "T056599",
          "T056598"
        ]
      },
      "release_date": "2026-07-14T22:00:00.000+00:00",
      "title": "CVE-2026-56821"
    },
    {
      "cve": "CVE-2026-56822",
      "product_status": {
        "known_affected": [
          "T056599",
          "T056598"
        ]
      },
      "release_date": "2026-07-14T22:00:00.000+00:00",
      "title": "CVE-2026-56822"
    },
    {
      "cve": "CVE-2026-59898",
      "product_status": {
        "known_affected": [
          "T056599",
          "T056598"
        ]
      },
      "release_date": "2026-07-14T22:00:00.000+00:00",
      "title": "CVE-2026-59898"
    },
    {
      "cve": "CVE-2026-59899",
      "product_status": {
        "known_affected": [
          "T056599",
          "T056598"
        ]
      },
      "release_date": "2026-07-14T22:00:00.000+00:00",
      "title": "CVE-2026-59899"
    },
    {
      "cve": "CVE-2026-59900",
      "product_status": {
        "known_affected": [
          "T056599",
          "T056598"
        ]
      },
      "release_date": "2026-07-14T22:00:00.000+00:00",
      "title": "CVE-2026-59900"
    },
    {
      "cve": "CVE-2026-59901",
      "product_status": {
        "known_affected": [
          "T056599",
          "T056598"
        ]
      },
      "release_date": "2026-07-14T22:00:00.000+00:00",
      "title": "CVE-2026-59901"
    },
    {
      "cve": "CVE-2026-59920",
      "product_status": {
        "known_affected": [
          "T056599",
          "T056598"
        ]
      },
      "release_date": "2026-07-14T22:00:00.000+00:00",
      "title": "CVE-2026-59920"
    },
    {
      "cve": "CVE-2026-59921",
      "product_status": {
        "known_affected": [
          "T056599",
          "T056598"
        ]
      },
      "release_date": "2026-07-14T22:00:00.000+00:00",
      "title": "CVE-2026-59921"
    }
  ]
}