GCVE Workshop - 22 September 2026 (14:00-18:00), Luxembourg Before The Vulnopticon Conference - Registration

CVE-2026-6042 (GCVE-0-2026-6042)

Vulnerability from cvelistv5 – Published: 2026-04-10 09:00 – Updated: 2026-04-10 15:54
VLAI
Title
musl libc GB18030 4-byte Decoder iconv.c iconv algorithmic complexity
Summary
A security flaw has been discovered in musl libc up to 1.2.6. Affected is the function iconv of the file src/locale/iconv.c of the component GB18030 4-byte Decoder. Performing a manipulation results in inefficient algorithmic complexity. The attack must be initiated from a local position. To fix this issue, it is recommended to deploy a patch.
SSVC
Exploitation: none Automatable: no Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-04-10 15:44 UTC
CWE
  • CWE-407 - Inefficient Algorithmic Complexity
  • CWE-404 - Denial of Service
Impacted products
Vendor Product Version CPE status
musl libc Affected: 1.2.0
Affected: 1.2.1
Affected: 1.2.2
Affected: 1.2.3
Affected: 1.2.4
Affected: 1.2.5
Affected: 1.2.6
guessed Create a notification for this product.
Show details on NVD website

{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2026-04-10T09:31:09.913Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "url": "http://www.openwall.com/lists/oss-security/2026/04/09/19"
          }
        ],
        "title": "CVE Program Container"
      },
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-6042",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-04-10T15:44:05.493056Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-04-10T15:54:06.200Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "modules": [
            "GB18030 4-byte Decoder"
          ],
          "product": "libc",
          "vendor": "musl",
          "versions": [
            {
              "status": "affected",
              "version": "1.2.0"
            },
            {
              "status": "affected",
              "version": "1.2.1"
            },
            {
              "status": "affected",
              "version": "1.2.2"
            },
            {
              "status": "affected",
              "version": "1.2.3"
            },
            {
              "status": "affected",
              "version": "1.2.4"
            },
            {
              "status": "affected",
              "version": "1.2.5"
            },
            {
              "status": "affected",
              "version": "1.2.6"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "reporter",
          "value": "0x001 (VulDB User)"
        },
        {
          "lang": "en",
          "type": "analyst",
          "value": "0x001 (VulDB User)"
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "A security flaw has been discovered in musl libc up to 1.2.6. Affected is the function iconv of the file src/locale/iconv.c of the component GB18030 4-byte Decoder. Performing a manipulation results in inefficient algorithmic complexity. The attack must be initiated from a local position. To fix this issue, it is recommended to deploy a patch."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "baseScore": 4.8,
            "baseSeverity": "MEDIUM",
            "vectorString": "CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X",
            "version": "4.0"
          }
        },
        {
          "cvssV3_1": {
            "baseScore": 3.3,
            "baseSeverity": "LOW",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L/E:X/RL:O/RC:C",
            "version": "3.1"
          }
        },
        {
          "cvssV3_0": {
            "baseScore": 3.3,
            "baseSeverity": "LOW",
            "vectorString": "CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L/E:X/RL:O/RC:C",
            "version": "3.0"
          }
        },
        {
          "cvssV2_0": {
            "baseScore": 1.7,
            "vectorString": "AV:L/AC:L/Au:S/C:N/I:N/A:P/E:ND/RL:OF/RC:C",
            "version": "2.0"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-407",
              "description": "Inefficient Algorithmic Complexity",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-404",
              "description": "Denial of Service",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-04-10T09:00:18.733Z",
        "orgId": "1af790b2-7ee1-4545-860a-a788eba489b5",
        "shortName": "VulDB"
      },
      "references": [
        {
          "name": "VDB-356620 | musl libc GB18030 4-byte Decoder iconv.c iconv algorithmic complexity",
          "tags": [
            "vdb-entry",
            "technical-description"
          ],
          "url": "https://vuldb.com/vuln/356620"
        },
        {
          "name": "VDB-356620 | CTI Indicators (IOB, IOC, IOA)",
          "tags": [
            "signature",
            "permissions-required"
          ],
          "url": "https://vuldb.com/vuln/356620/cti"
        },
        {
          "name": "Submit #796352 | musl libc musl 0.8.0 - 1.2.6 Inefficient Algorithmic Complexity",
          "tags": [
            "third-party-advisory"
          ],
          "url": "https://vuldb.com/submit/796352"
        },
        {
          "tags": [
            "related"
          ],
          "url": "https://www.openwall.com/lists/oss-security/2026/04/02/10"
        },
        {
          "tags": [
            "patch"
          ],
          "url": "https://www.openwall.com/lists/oss-security/2026/04/03/2"
        }
      ],
      "timeline": [
        {
          "lang": "en",
          "time": "2026-04-09T00:00:00.000Z",
          "value": "Advisory disclosed"
        },
        {
          "lang": "en",
          "time": "2026-04-09T02:00:00.000Z",
          "value": "VulDB entry created"
        },
        {
          "lang": "en",
          "time": "2026-04-09T19:58:49.000Z",
          "value": "VulDB entry last update"
        }
      ],
      "title": "musl libc GB18030 4-byte Decoder iconv.c iconv algorithmic complexity"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "1af790b2-7ee1-4545-860a-a788eba489b5",
    "assignerShortName": "VulDB",
    "cveId": "CVE-2026-6042",
    "datePublished": "2026-04-10T09:00:18.733Z",
    "dateReserved": "2026-04-09T17:34:11.256Z",
    "dateUpdated": "2026-04-10T15:54:06.200Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-6042",
      "date": "2026-09-15",
      "epss": "0.00236",
      "percentile": "0.14691"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-6042\",\"sourceIdentifier\":\"cna@vuldb.com\",\"published\":\"2026-04-10T09:16:25.450\",\"lastModified\":\"2026-06-17T11:00:13.667\",\"vulnStatus\":\"Deferred\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"A security flaw has been discovered in musl libc up to 1.2.6. Affected is the function iconv of the file src/locale/iconv.c of the component GB18030 4-byte Decoder. Performing a manipulation results in inefficient algorithmic complexity. The attack must be initiated from a local position. To fix this issue, it is recommended to deploy a patch.\"}],\"affected\":[{\"source\":\"cna@vuldb.com\",\"affectedData\":[{\"vendor\":\"musl\",\"product\":\"libc\",\"modules\":[\"GB18030 4-byte Decoder\"],\"versions\":[{\"version\":\"1.2.0\",\"status\":\"affected\"},{\"version\":\"1.2.1\",\"status\":\"affected\"},{\"version\":\"1.2.2\",\"status\":\"affected\"},{\"version\":\"1.2.3\",\"status\":\"affected\"},{\"version\":\"1.2.4\",\"status\":\"affected\"},{\"version\":\"1.2.5\",\"status\":\"affected\"},{\"version\":\"1.2.6\",\"status\":\"affected\"}]}]}],\"metrics\":{\"cvssMetricV40\":[{\"source\":\"cna@vuldb.com\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"4.0\",\"vectorString\":\"CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/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:X/AU:X/R:X/V:X/RE:X/U:X\",\"baseScore\":4.8,\"baseSeverity\":\"MEDIUM\",\"attackVector\":\"LOCAL\",\"attackComplexity\":\"LOW\",\"attackRequirements\":\"NONE\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"vulnConfidentialityImpact\":\"NONE\",\"vulnIntegrityImpact\":\"NONE\",\"vulnAvailabilityImpact\":\"LOW\",\"subConfidentialityImpact\":\"NONE\",\"subIntegrityImpact\":\"NONE\",\"subAvailabilityImpact\":\"NONE\",\"exploitMaturity\":\"NOT_DEFINED\",\"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\":\"NOT_DEFINED\",\"Automatable\":\"NOT_DEFINED\",\"Recovery\":\"NOT_DEFINED\",\"valueDensity\":\"NOT_DEFINED\",\"vulnerabilityResponseEffort\":\"NOT_DEFINED\",\"providerUrgency\":\"NOT_DEFINED\"}}],\"cvssMetricV31\":[{\"source\":\"cna@vuldb.com\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L\",\"baseScore\":3.3,\"baseSeverity\":\"LOW\",\"attackVector\":\"LOCAL\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"NONE\",\"integrityImpact\":\"NONE\",\"availabilityImpact\":\"LOW\"},\"exploitabilityScore\":1.8,\"impactScore\":1.4}],\"cvssMetricV2\":[{\"source\":\"cna@vuldb.com\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"2.0\",\"vectorString\":\"AV:L/AC:L/Au:S/C:N/I:N/A:P\",\"baseScore\":1.7,\"accessVector\":\"LOCAL\",\"accessComplexity\":\"LOW\",\"authentication\":\"SINGLE\",\"confidentialityImpact\":\"NONE\",\"integrityImpact\":\"NONE\",\"availabilityImpact\":\"PARTIAL\"},\"baseSeverity\":\"LOW\",\"exploitabilityScore\":3.1,\"impactScore\":2.9,\"acInsufInfo\":false,\"obtainAllPrivilege\":false,\"obtainUserPrivilege\":false,\"obtainOtherPrivilege\":false,\"userInteractionRequired\":false}],\"ssvcV203\":[{\"source\":\"134c704f-9b21-4f2e-91b3-4a467353bcc0\",\"ssvcData\":{\"timestamp\":\"2026-04-10T15:44:05.493056Z\",\"id\":\"CVE-2026-6042\",\"options\":[{\"exploitation\":\"none\"},{\"automatable\":\"no\"},{\"technicalImpact\":\"partial\"}],\"role\":\"CISA Coordinator\",\"version\":\"2.0.3\"}}]},\"weaknesses\":[{\"source\":\"cna@vuldb.com\",\"type\":\"Secondary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-404\"},{\"lang\":\"en\",\"value\":\"CWE-407\"}]}],\"references\":[{\"url\":\"https://vuldb.com/submit/796352\",\"source\":\"cna@vuldb.com\"},{\"url\":\"https://vuldb.com/vuln/356620\",\"source\":\"cna@vuldb.com\"},{\"url\":\"https://vuldb.com/vuln/356620/cti\",\"source\":\"cna@vuldb.com\"},{\"url\":\"https://www.openwall.com/lists/oss-security/2026/04/02/10\",\"source\":\"cna@vuldb.com\"},{\"url\":\"https://www.openwall.com/lists/oss-security/2026/04/03/2\",\"source\":\"cna@vuldb.com\"},{\"url\":\"http://www.openwall.com/lists/oss-security/2026/04/09/19\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\"}]}}",
    "redhat_vex": {
      "current_release_date": "2026-06-28T07:45:35+00:00",
      "cve": "CVE-2026-6042",
      "id": "CVE-2026-6042",
      "initial_release_date": "2026-04-10T09:00:18.733000+00:00",
      "product_status:known_not_affected": "1",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "musl libc: GB18030 4-byte Decoder: musl libc: Denial of Service via inefficient algorithmic complexity in iconv",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-6042.json",
      "version": "3"
    },
    "vulnrichment": {
      "containers": "{\"adp\": [{\"title\": \"CVE Program Container\", \"references\": [{\"url\": \"http://www.openwall.com/lists/oss-security/2026/04/09/19\"}], \"providerMetadata\": {\"orgId\": \"af854a3a-2127-422b-91ae-364da2661108\", \"shortName\": \"CVE\", \"dateUpdated\": \"2026-04-10T09:31:09.913Z\"}}, {\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-6042\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"none\"}, {\"Automatable\": \"no\"}, {\"Technical Impact\": \"partial\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-04-10T15:44:05.493056Z\"}}}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-04-10T15:44:17.351Z\"}}], \"cna\": {\"title\": \"musl libc GB18030 4-byte Decoder iconv.c iconv algorithmic complexity\", \"credits\": [{\"lang\": \"en\", \"type\": \"reporter\", \"value\": \"0x001 (VulDB User)\"}, {\"lang\": \"en\", \"type\": \"analyst\", \"value\": \"0x001 (VulDB User)\"}], \"metrics\": [{\"cvssV4_0\": {\"version\": \"4.0\", \"baseScore\": 4.8, \"baseSeverity\": \"MEDIUM\", \"vectorString\": \"CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X\"}}, {\"cvssV3_1\": {\"version\": \"3.1\", \"baseScore\": 3.3, \"baseSeverity\": \"LOW\", \"vectorString\": \"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L/E:X/RL:O/RC:C\"}}, {\"cvssV3_0\": {\"version\": \"3.0\", \"baseScore\": 3.3, \"baseSeverity\": \"LOW\", \"vectorString\": \"CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L/E:X/RL:O/RC:C\"}}, {\"cvssV2_0\": {\"version\": \"2.0\", \"baseScore\": 1.7, \"vectorString\": \"AV:L/AC:L/Au:S/C:N/I:N/A:P/E:ND/RL:OF/RC:C\"}}], \"affected\": [{\"vendor\": \"musl\", \"modules\": [\"GB18030 4-byte Decoder\"], \"product\": \"libc\", \"versions\": [{\"status\": \"affected\", \"version\": \"1.2.0\"}, {\"status\": \"affected\", \"version\": \"1.2.1\"}, {\"status\": \"affected\", \"version\": \"1.2.2\"}, {\"status\": \"affected\", \"version\": \"1.2.3\"}, {\"status\": \"affected\", \"version\": \"1.2.4\"}, {\"status\": \"affected\", \"version\": \"1.2.5\"}, {\"status\": \"affected\", \"version\": \"1.2.6\"}]}], \"timeline\": [{\"lang\": \"en\", \"time\": \"2026-04-09T00:00:00.000Z\", \"value\": \"Advisory disclosed\"}, {\"lang\": \"en\", \"time\": \"2026-04-09T02:00:00.000Z\", \"value\": \"VulDB entry created\"}, {\"lang\": \"en\", \"time\": \"2026-04-09T19:58:49.000Z\", \"value\": \"VulDB entry last update\"}], \"references\": [{\"url\": \"https://vuldb.com/vuln/356620\", \"name\": \"VDB-356620 | musl libc GB18030 4-byte Decoder iconv.c iconv algorithmic complexity\", \"tags\": [\"vdb-entry\", \"technical-description\"]}, {\"url\": \"https://vuldb.com/vuln/356620/cti\", \"name\": \"VDB-356620 | CTI Indicators (IOB, IOC, IOA)\", \"tags\": [\"signature\", \"permissions-required\"]}, {\"url\": \"https://vuldb.com/submit/796352\", \"name\": \"Submit #796352 | musl libc musl 0.8.0 - 1.2.6 Inefficient Algorithmic Complexity\", \"tags\": [\"third-party-advisory\"]}, {\"url\": \"https://www.openwall.com/lists/oss-security/2026/04/02/10\", \"tags\": [\"related\"]}, {\"url\": \"https://www.openwall.com/lists/oss-security/2026/04/03/2\", \"tags\": [\"patch\"]}], \"descriptions\": [{\"lang\": \"en\", \"value\": \"A security flaw has been discovered in musl libc up to 1.2.6. Affected is the function iconv of the file src/locale/iconv.c of the component GB18030 4-byte Decoder. Performing a manipulation results in inefficient algorithmic complexity. The attack must be initiated from a local position. To fix this issue, it is recommended to deploy a patch.\"}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-407\", \"description\": \"Inefficient Algorithmic Complexity\"}]}, {\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-404\", \"description\": \"Denial of Service\"}]}], \"providerMetadata\": {\"orgId\": \"1af790b2-7ee1-4545-860a-a788eba489b5\", \"shortName\": \"VulDB\", \"dateUpdated\": \"2026-04-10T09:00:18.733Z\"}}}",
      "cveMetadata": "{\"cveId\": \"CVE-2026-6042\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-04-10T15:54:06.200Z\", \"dateReserved\": \"2026-04-09T17:34:11.256Z\", \"assignerOrgId\": \"1af790b2-7ee1-4545-860a-a788eba489b5\", \"datePublished\": \"2026-04-10T09:00:18.733Z\", \"assignerShortName\": \"VulDB\"}",
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.


Loading…

Loading…

Loading…

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.

Loading…

Detection rules are retrieved from Rulezet.

Loading…

Loading…

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.


Loading…