CVE-2026-39829 (GCVE-0-2026-39829)

Vulnerability from cvelistv5 – Published: 2026-05-22 02:31 – Updated: 2026-05-22 18:53
VLAI
Title
Invoking pathological RSA/DSA parameters may cause DoS in golang.org/x/crypto/ssh
Summary
The RSA and DSA public key parsers did not enforce size limits on key parameters. A crafted public key with an excessively large modulus or DSA parameter could cause several minutes of CPU consumption during signature verification. This could be triggered by unauthenticated clients during public key authentication. RSA moduli are now limited to 8192 bits, and DSA parameters are validated per FIPS 186-2.
Severity
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
SSVC
Exploitation: none Automatable: yes Technical Impact: partial
CISA Coordinator (v2.0.3)
CWE
  • CWE-1176 - Inefficient CPU Computation
Assigner
Go
References
Impacted products
Vendor Product Version
golang.org/x/crypto golang.org/x/crypto/ssh Affected: 0 , < 0.52.0 (semver)
Create a notification for this product.
Credits
NCC Group Cryptography Services, sponsored by Teleport
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "cvssV3_1": {
              "attackComplexity": "LOW",
              "attackVector": "NETWORK",
              "availabilityImpact": "HIGH",
              "baseScore": 7.5,
              "baseSeverity": "HIGH",
              "confidentialityImpact": "NONE",
              "integrityImpact": "NONE",
              "privilegesRequired": "NONE",
              "scope": "UNCHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
              "version": "3.1"
            }
          },
          {
            "other": {
              "content": {
                "id": "CVE-2026-39829",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-05-22T18:52:38.155082Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-05-22T18:53:33.377Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "collectionURL": "https://pkg.go.dev",
          "defaultStatus": "unaffected",
          "packageName": "golang.org/x/crypto/ssh",
          "product": "golang.org/x/crypto/ssh",
          "programRoutines": [
            {
              "name": "parseRSA"
            },
            {
              "name": "checkDSAParams"
            },
            {
              "name": "parseDSA"
            },
            {
              "name": "Dial"
            },
            {
              "name": "NewClientConn"
            },
            {
              "name": "NewServerConn"
            },
            {
              "name": "NewSignerFromKey"
            },
            {
              "name": "ParseAuthorizedKey"
            },
            {
              "name": "ParseKnownHosts"
            },
            {
              "name": "ParsePrivateKey"
            },
            {
              "name": "ParsePrivateKeyWithPassphrase"
            },
            {
              "name": "ParsePublicKey"
            },
            {
              "name": "ParseRawPrivateKey"
            },
            {
              "name": "ParseRawPrivateKeyWithPassphrase"
            }
          ],
          "vendor": "golang.org/x/crypto",
          "versions": [
            {
              "lessThan": "0.52.0",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "value": "NCC Group Cryptography Services, sponsored by Teleport"
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "The RSA and DSA public key parsers did not enforce size limits on key parameters. A crafted public key with an excessively large modulus or DSA parameter could cause several minutes of CPU consumption during signature verification. This could be triggered by unauthenticated clients during public key authentication. RSA moduli are now limited to 8192 bits, and DSA parameters are validated per FIPS 186-2."
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "description": "CWE-1176: Inefficient CPU Computation",
              "lang": "en"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-22T02:31:27.324Z",
        "orgId": "1bb62c36-49e3-4200-9d77-64a1400537cc",
        "shortName": "Go"
      },
      "references": [
        {
          "url": "https://go.dev/issue/79565"
        },
        {
          "url": "https://groups.google.com/g/golang-announce/c/a082jnz-LvI"
        },
        {
          "url": "https://go.dev/cl/781641"
        },
        {
          "url": "https://go.dev/cl/781661"
        },
        {
          "url": "https://pkg.go.dev/vuln/GO-2026-5018"
        }
      ],
      "title": "Invoking  pathological RSA/DSA parameters may cause DoS in golang.org/x/crypto/ssh"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "1bb62c36-49e3-4200-9d77-64a1400537cc",
    "assignerShortName": "Go",
    "cveId": "CVE-2026-39829",
    "datePublished": "2026-05-22T02:31:27.324Z",
    "dateReserved": "2026-04-07T18:13:03.528Z",
    "dateUpdated": "2026-05-22T18:53:33.377Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-39829",
      "date": "2026-06-26",
      "epss": "0.00304",
      "percentile": "0.22027"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-39829\",\"sourceIdentifier\":\"security@golang.org\",\"published\":\"2026-05-22T04:16:22.310\",\"lastModified\":\"2026-06-02T16:33:46.800\",\"vulnStatus\":\"Analyzed\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"The RSA and DSA public key parsers did not enforce size limits on key parameters. A crafted public key with an excessively large modulus or DSA parameter could cause several minutes of CPU consumption during signature verification. This could be triggered by unauthenticated clients during public key authentication. RSA moduli are now limited to 8192 bits, and DSA parameters are validated per FIPS 186-2.\"}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"134c704f-9b21-4f2e-91b3-4a467353bcc0\",\"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}]},\"weaknesses\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-347\"}]}],\"configurations\":[{\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:a:golang:crypto:*:*:*:*:*:go:*:*\",\"versionEndExcluding\":\"0.52.0\",\"matchCriteriaId\":\"D540395B-31B8-4B07-8F79-F5C631BBD5C8\"}]}]}],\"references\":[{\"url\":\"https://go.dev/cl/781641\",\"source\":\"security@golang.org\",\"tags\":[\"Issue Tracking\"]},{\"url\":\"https://go.dev/cl/781661\",\"source\":\"security@golang.org\",\"tags\":[\"Issue Tracking\"]},{\"url\":\"https://go.dev/issue/79565\",\"source\":\"security@golang.org\",\"tags\":[\"Issue Tracking\"]},{\"url\":\"https://groups.google.com/g/golang-announce/c/a082jnz-LvI\",\"source\":\"security@golang.org\",\"tags\":[\"Mailing List\"]},{\"url\":\"https://pkg.go.dev/vuln/GO-2026-5018\",\"source\":\"security@golang.org\",\"tags\":[\"Vendor Advisory\"]}]}}",
    "vulnrichment": {
      "containers": "{\"adp\": [{\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"cvssV3_1\": {\"scope\": \"UNCHANGED\", \"version\": \"3.1\", \"baseScore\": 7.5, \"attackVector\": \"NETWORK\", \"baseSeverity\": \"HIGH\", \"vectorString\": \"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H\", \"integrityImpact\": \"NONE\", \"userInteraction\": \"NONE\", \"attackComplexity\": \"LOW\", \"availabilityImpact\": \"HIGH\", \"privilegesRequired\": \"NONE\", \"confidentialityImpact\": \"NONE\"}}, {\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-39829\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"none\"}, {\"Automatable\": \"yes\"}, {\"Technical Impact\": \"partial\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-05-22T18:52:38.155082Z\"}}}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-05-22T18:53:29.195Z\"}}], \"cna\": {\"title\": \"Invoking  pathological RSA/DSA parameters may cause DoS in golang.org/x/crypto/ssh\", \"credits\": [{\"lang\": \"en\", \"value\": \"NCC Group Cryptography Services, sponsored by Teleport\"}], \"affected\": [{\"vendor\": \"golang.org/x/crypto\", \"product\": \"golang.org/x/crypto/ssh\", \"versions\": [{\"status\": \"affected\", \"version\": \"0\", \"lessThan\": \"0.52.0\", \"versionType\": \"semver\"}], \"packageName\": \"golang.org/x/crypto/ssh\", \"collectionURL\": \"https://pkg.go.dev\", \"defaultStatus\": \"unaffected\", \"programRoutines\": [{\"name\": \"parseRSA\"}, {\"name\": \"checkDSAParams\"}, {\"name\": \"parseDSA\"}, {\"name\": \"Dial\"}, {\"name\": \"NewClientConn\"}, {\"name\": \"NewServerConn\"}, {\"name\": \"NewSignerFromKey\"}, {\"name\": \"ParseAuthorizedKey\"}, {\"name\": \"ParseKnownHosts\"}, {\"name\": \"ParsePrivateKey\"}, {\"name\": \"ParsePrivateKeyWithPassphrase\"}, {\"name\": \"ParsePublicKey\"}, {\"name\": \"ParseRawPrivateKey\"}, {\"name\": \"ParseRawPrivateKeyWithPassphrase\"}]}], \"references\": [{\"url\": \"https://go.dev/issue/79565\"}, {\"url\": \"https://groups.google.com/g/golang-announce/c/a082jnz-LvI\"}, {\"url\": \"https://go.dev/cl/781641\"}, {\"url\": \"https://go.dev/cl/781661\"}, {\"url\": \"https://pkg.go.dev/vuln/GO-2026-5018\"}], \"descriptions\": [{\"lang\": \"en\", \"value\": \"The RSA and DSA public key parsers did not enforce size limits on key parameters. A crafted public key with an excessively large modulus or DSA parameter could cause several minutes of CPU consumption during signature verification. This could be triggered by unauthenticated clients during public key authentication. RSA moduli are now limited to 8192 bits, and DSA parameters are validated per FIPS 186-2.\"}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"description\": \"CWE-1176: Inefficient CPU Computation\"}]}], \"providerMetadata\": {\"orgId\": \"1bb62c36-49e3-4200-9d77-64a1400537cc\", \"shortName\": \"Go\", \"dateUpdated\": \"2026-05-22T02:31:27.324Z\"}}}",
      "cveMetadata": "{\"cveId\": \"CVE-2026-39829\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-05-22T18:53:33.377Z\", \"dateReserved\": \"2026-04-07T18:13:03.528Z\", \"assignerOrgId\": \"1bb62c36-49e3-4200-9d77-64a1400537cc\", \"datePublished\": \"2026-05-22T02:31:27.324Z\", \"assignerShortName\": \"Go\"}",
      "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.