CVE-2026-5598 (GCVE-0-2026-5598)

Vulnerability from cvelistv5 – Published: 2026-04-15 09:05 – Updated: 2026-05-18 23:17
VLAI?
Title
Non-constant time comparisons risk private key leakage in FrodoKEM.
Summary
Covert timing channel vulnerability in Legion of the Bouncy Castle Inc. BC-JAVA core on all (core modules). This vulnerability is associated with program files FrodoEngine.Java. This issue affects BC-JAVA: from 1.71 before 1.80.2, from 1.81 before 1.80.1, from 1.82 before 1.84.
Severity ?
8.9 (High)
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N/E:U/S:P/AU:Y/U:Red
CWE
Assigner
References
Impacted products
Vendor Product Version
Legion of the Bouncy Castle Inc. BC-JAVA Affected: 1.71 , < 1.80.2 (maven)
Affected: 1.81 , < 1.80.1 (maven)
Affected: 1.82 , < 1.84 (maven)
Create a notification for this product.
Credits
Cristina Dueñas Navarro (cristina.duenas@jtsec.es) Sunwoo Lee and Seunghyun Yoon, Korea Institute of Energy Technology (KENTECH)
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-5598",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-04-15T13:11:48.318645Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-04-15T13:11:53.444Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "collectionURL": "https://www.bouncycastle.org/download/bouncy-castle-java/",
          "defaultStatus": "unaffected",
          "modules": [
            "core"
          ],
          "packageName": "core",
          "platforms": [
            "all"
          ],
          "product": "BC-JAVA",
          "programFiles": [
            "FrodoEngine.java"
          ],
          "repo": "https://github.com/bcgit/bc-java",
          "vendor": "Legion of the Bouncy Castle Inc.",
          "versions": [
            {
              "lessThan": "1.80.2",
              "status": "affected",
              "version": "1.71",
              "versionType": "maven"
            },
            {
              "lessThan": "1.80.1",
              "status": "affected",
              "version": "1.81",
              "versionType": "maven"
            },
            {
              "lessThan": "1.84",
              "status": "affected",
              "version": "1.82",
              "versionType": "maven"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "Cristina Due\u00f1as Navarro (cristina.duenas@jtsec.es)"
        },
        {
          "lang": "en",
          "type": "finder",
          "value": "Sunwoo Lee and Seunghyun Yoon, Korea Institute of Energy Technology (KENTECH)"
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "supportingMedia": [
            {
              "base64": false,
              "type": "text/html",
              "value": "Covert timing channel vulnerability in Legion of the Bouncy Castle Inc. BC-JAVA core on all (core modules).\u003cp\u003e This vulnerability is associated with program files FrodoEngine.Java.\u003c/p\u003e\u003cp\u003eThis issue affects BC-JAVA: from 1.71 before 1.80.2, from 1.81 before 1.80.1, from 1.82 before 1.84.\u003c/p\u003e"
            }
          ],
          "value": "Covert timing channel vulnerability in Legion of the Bouncy Castle Inc. BC-JAVA core on all (core modules).\n\n This vulnerability is associated with program files FrodoEngine.Java.\n\n\n\nThis issue affects BC-JAVA: from 1.71 before 1.80.2, from 1.81 before 1.80.1, from 1.82 before 1.84."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "Automatable": "YES",
            "Recovery": "NOT_DEFINED",
            "Safety": "PRESENT",
            "attackComplexity": "LOW",
            "attackRequirements": "NONE",
            "attackVector": "NETWORK",
            "baseScore": 8.9,
            "baseSeverity": "HIGH",
            "exploitMaturity": "UNREPORTED",
            "privilegesRequired": "NONE",
            "providerUrgency": "RED",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "HIGH",
            "subIntegrityImpact": "HIGH",
            "userInteraction": "NONE",
            "valueDensity": "NOT_DEFINED",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N/E:U/S:P/AU:Y/U:Red",
            "version": "4.0",
            "vulnAvailabilityImpact": "NONE",
            "vulnConfidentialityImpact": "HIGH",
            "vulnIntegrityImpact": "HIGH",
            "vulnerabilityResponseEffort": "NOT_DEFINED"
          },
          "format": "CVSS",
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
            }
          ]
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-385",
              "description": "CWE-385 Covert timing channel",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-18T23:17:39.880Z",
        "orgId": "91579145-5d7b-4cc5-b925-a0262ff19630",
        "shortName": "bcorg"
      },
      "references": [
        {
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://github.com/bcgit/bc-java/wiki/CVE%E2%80%902026%E2%80%905598"
        },
        {
          "tags": [
            "patch"
          ],
          "url": "https://github.com/bcgit/bc-java/commit/94abbd56413dfdac651fd878bc60253871ef5e87"
        },
        {
          "tags": [
            "patch"
          ],
          "url": "https://github.com/bcgit/bc-java/commit/8692e6b2b191fc4aafa32545c7a78bdb9bf110c5"
        }
      ],
      "source": {
        "discovery": "UNKNOWN"
      },
      "title": "Non-constant time comparisons risk private key leakage in FrodoKEM.",
      "x_generator": {
        "engine": "Vulnogram 1.0.1"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "91579145-5d7b-4cc5-b925-a0262ff19630",
    "assignerShortName": "bcorg",
    "cveId": "CVE-2026-5598",
    "datePublished": "2026-04-15T09:05:56.277Z",
    "dateReserved": "2026-04-05T07:25:44.930Z",
    "dateUpdated": "2026-05-18T23:17:39.880Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-5598",
      "date": "2026-05-18",
      "epss": "0.0002",
      "percentile": "0.05604"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-5598\",\"sourceIdentifier\":\"91579145-5d7b-4cc5-b925-a0262ff19630\",\"published\":\"2026-04-15T10:16:49.757\",\"lastModified\":\"2026-05-19T00:16:37.773\",\"vulnStatus\":\"Awaiting Analysis\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"Covert timing channel vulnerability in Legion of the Bouncy Castle Inc. BC-JAVA core on all (core modules).\\n\\n This vulnerability is associated with program files FrodoEngine.Java.\\n\\n\\n\\nThis issue affects BC-JAVA: from 1.71 before 1.80.2, from 1.81 before 1.80.1, from 1.82 before 1.84.\"}],\"metrics\":{\"cvssMetricV40\":[{\"source\":\"91579145-5d7b-4cc5-b925-a0262ff19630\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"4.0\",\"vectorString\":\"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N/E:U/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:P/AU:Y/R:X/V:X/RE:X/U:Red\",\"baseScore\":8.9,\"baseSeverity\":\"HIGH\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"attackRequirements\":\"NONE\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"NONE\",\"vulnConfidentialityImpact\":\"HIGH\",\"vulnIntegrityImpact\":\"HIGH\",\"vulnAvailabilityImpact\":\"NONE\",\"subConfidentialityImpact\":\"HIGH\",\"subIntegrityImpact\":\"HIGH\",\"subAvailabilityImpact\":\"NONE\",\"exploitMaturity\":\"UNREPORTED\",\"confidentialityRequirement\":\"NOT_DEFINED\",\"integrityRequirement\":\"NOT_DEFINED\",\"availabilityRequirement\":\"NOT_DEFINED\",\"modifiedAttackVector\":\"NOT_DEFINED\",\"modifiedAttackComplexity\":\"NOT_DEFINED\",\"modifiedAttackRequirements\":\"NOT_DEFINED\",\"modifiedPrivilegesRequired\":\"NOT_DEFINED\",\"modifiedUserInteraction\":\"NOT_DEFINED\",\"modifiedVulnConfidentialityImpact\":\"NOT_DEFINED\",\"modifiedVulnIntegrityImpact\":\"NOT_DEFINED\",\"modifiedVulnAvailabilityImpact\":\"NOT_DEFINED\",\"modifiedSubConfidentialityImpact\":\"NOT_DEFINED\",\"modifiedSubIntegrityImpact\":\"NOT_DEFINED\",\"modifiedSubAvailabilityImpact\":\"NOT_DEFINED\",\"Safety\":\"PRESENT\",\"Automatable\":\"YES\",\"Recovery\":\"NOT_DEFINED\",\"valueDensity\":\"NOT_DEFINED\",\"vulnerabilityResponseEffort\":\"NOT_DEFINED\",\"providerUrgency\":\"RED\"}}]},\"weaknesses\":[{\"source\":\"91579145-5d7b-4cc5-b925-a0262ff19630\",\"type\":\"Secondary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-385\"}]}],\"references\":[{\"url\":\"https://github.com/bcgit/bc-java/commit/8692e6b2b191fc4aafa32545c7a78bdb9bf110c5\",\"source\":\"91579145-5d7b-4cc5-b925-a0262ff19630\"},{\"url\":\"https://github.com/bcgit/bc-java/commit/94abbd56413dfdac651fd878bc60253871ef5e87\",\"source\":\"91579145-5d7b-4cc5-b925-a0262ff19630\"},{\"url\":\"https://github.com/bcgit/bc-java/wiki/CVE%E2%80%902026%E2%80%905598\",\"source\":\"91579145-5d7b-4cc5-b925-a0262ff19630\"}]}}",
    "vulnrichment": {
      "containers": "{\"adp\": [{\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-5598\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"none\"}, {\"Automatable\": \"yes\"}, {\"Technical Impact\": \"total\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-04-15T13:11:48.318645Z\"}}}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-04-15T13:11:50.359Z\"}}], \"cna\": {\"title\": \"Non-constant time comparisons risk private key leakage in FrodoKEM.\", \"source\": {\"discovery\": \"UNKNOWN\"}, \"credits\": [{\"lang\": \"en\", \"type\": \"finder\", \"value\": \"Cristina Due\\u00f1as Navarro (cristina.duenas@jtsec.es)\"}, {\"lang\": \"en\", \"type\": \"finder\", \"value\": \"Sunwoo Lee and Seunghyun Yoon, Korea Institute of Energy Technology (KENTECH)\"}], \"metrics\": [{\"format\": \"CVSS\", \"cvssV4_0\": {\"Safety\": \"PRESENT\", \"version\": \"4.0\", \"Recovery\": \"NOT_DEFINED\", \"baseScore\": 8.9, \"Automatable\": \"YES\", \"attackVector\": \"NETWORK\", \"baseSeverity\": \"HIGH\", \"valueDensity\": \"NOT_DEFINED\", \"vectorString\": \"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N/E:U/S:P/AU:Y/U:Red\", \"exploitMaturity\": \"UNREPORTED\", \"providerUrgency\": \"RED\", \"userInteraction\": \"NONE\", \"attackComplexity\": \"LOW\", \"attackRequirements\": \"NONE\", \"privilegesRequired\": \"NONE\", \"subIntegrityImpact\": \"HIGH\", \"vulnIntegrityImpact\": \"HIGH\", \"subAvailabilityImpact\": \"NONE\", \"vulnAvailabilityImpact\": \"NONE\", \"subConfidentialityImpact\": \"HIGH\", \"vulnConfidentialityImpact\": \"HIGH\", \"vulnerabilityResponseEffort\": \"NOT_DEFINED\"}, \"scenarios\": [{\"lang\": \"en\", \"value\": \"GENERAL\"}]}], \"affected\": [{\"repo\": \"https://github.com/bcgit/bc-java\", \"vendor\": \"Legion of the Bouncy Castle Inc.\", \"modules\": [\"core\"], \"product\": \"BC-JAVA\", \"versions\": [{\"status\": \"affected\", \"version\": \"1.71\", \"lessThan\": \"1.80.2\", \"versionType\": \"maven\"}, {\"status\": \"affected\", \"version\": \"1.81\", \"lessThan\": \"1.80.1\", \"versionType\": \"maven\"}, {\"status\": \"affected\", \"version\": \"1.82\", \"lessThan\": \"1.84\", \"versionType\": \"maven\"}], \"platforms\": [\"all\"], \"packageName\": \"core\", \"programFiles\": [\"FrodoEngine.java\"], \"collectionURL\": \"https://www.bouncycastle.org/download/bouncy-castle-java/\", \"defaultStatus\": \"unaffected\"}], \"references\": [{\"url\": \"https://github.com/bcgit/bc-java/wiki/CVE%E2%80%902026%E2%80%905598\", \"tags\": [\"vendor-advisory\"]}, {\"url\": \"https://github.com/bcgit/bc-java/commit/94abbd56413dfdac651fd878bc60253871ef5e87\", \"tags\": [\"patch\"]}, {\"url\": \"https://github.com/bcgit/bc-java/commit/8692e6b2b191fc4aafa32545c7a78bdb9bf110c5\", \"tags\": [\"patch\"]}], \"x_generator\": {\"engine\": \"Vulnogram 1.0.1\"}, \"descriptions\": [{\"lang\": \"en\", \"value\": \"Covert timing channel vulnerability in Legion of the Bouncy Castle Inc. BC-JAVA core on all (core modules).\\n\\n This vulnerability is associated with program files FrodoEngine.Java.\\n\\n\\n\\nThis issue affects BC-JAVA: from 1.71 before 1.80.2, from 1.81 before 1.80.1, from 1.82 before 1.84.\", \"supportingMedia\": [{\"type\": \"text/html\", \"value\": \"Covert timing channel vulnerability in Legion of the Bouncy Castle Inc. BC-JAVA core on all (core modules).\u003cp\u003e This vulnerability is associated with program files FrodoEngine.Java.\u003c/p\u003e\u003cp\u003eThis issue affects BC-JAVA: from 1.71 before 1.80.2, from 1.81 before 1.80.1, from 1.82 before 1.84.\u003c/p\u003e\", \"base64\": false}]}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-385\", \"description\": \"CWE-385 Covert timing channel\"}]}], \"providerMetadata\": {\"orgId\": \"91579145-5d7b-4cc5-b925-a0262ff19630\", \"shortName\": \"bcorg\", \"dateUpdated\": \"2026-05-18T23:17:39.880Z\"}}}",
      "cveMetadata": "{\"cveId\": \"CVE-2026-5598\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-05-18T23:17:39.880Z\", \"dateReserved\": \"2026-04-05T07:25:44.930Z\", \"assignerOrgId\": \"91579145-5d7b-4cc5-b925-a0262ff19630\", \"datePublished\": \"2026-04-15T09:05:56.277Z\", \"assignerShortName\": \"bcorg\"}",
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



Detection rules are retrieved from Rulezet.