CVE-2026-34840 (GCVE-0-2026-34840)

Vulnerability from cvelistv5 – Published: 2026-04-02 18:52 – Updated: 2026-04-02 20:20
VLAI
Title
OneUptime SSO: Multi-Assertion Identity Injection via Decoupled Signature Verification
Summary
OneUptime is an open-source monitoring and observability platform. Prior to version 10.0.42, OneUptime's SAML SSO implementation (App/FeatureSet/Identity/Utils/SSO.ts) has decoupled signature verification and identity extraction. isSignatureValid() verifies the first <Signature> element in the XML DOM using xml-crypto, while getEmail() always reads from assertion[0] via xml2js. An attacker can prepend an unsigned assertion containing an arbitrary identity before a legitimately signed assertion, resulting in authentication bypass. This issue has been patched in version 10.0.42.
Severity
8.1 (High)
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
SSVC
Exploitation: poc Automatable: no Technical Impact: total
CISA Coordinator (v2.0.3)
CWE
  • CWE-347 - Improper Verification of Cryptographic Signature
Assigner
References
Impacted products
Vendor Product Version
OneUptime oneuptime Affected: < 10.0.42
Create a notification for this product.
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-34840",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-04-02T20:20:03.529115Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-04-02T20:20:13.291Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "oneuptime",
          "vendor": "OneUptime",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 10.0.42"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "OneUptime is an open-source monitoring and observability platform. Prior to version 10.0.42, OneUptime\u0027s SAML SSO implementation (App/FeatureSet/Identity/Utils/SSO.ts) has decoupled signature verification and identity extraction. isSignatureValid() verifies the first \u003cSignature\u003e element in the XML DOM using xml-crypto, while getEmail() always reads from assertion[0] via xml2js. An attacker can prepend an unsigned assertion containing an arbitrary identity before a legitimately signed assertion, resulting in authentication bypass. This issue has been patched in version 10.0.42."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 8.1,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "LOW",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-347",
              "description": "CWE-347: Improper Verification of Cryptographic Signature",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-04-02T18:52:48.274Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/OneUptime/oneuptime/security/advisories/GHSA-5w5c-766x-265g",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/OneUptime/oneuptime/security/advisories/GHSA-5w5c-766x-265g"
        },
        {
          "name": "https://github.com/OneUptime/oneuptime/commit/2fd7ede52f60444710628d6c1b34dee2ef9e57d1",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/OneUptime/oneuptime/commit/2fd7ede52f60444710628d6c1b34dee2ef9e57d1"
        },
        {
          "name": "https://github.com/OneUptime/oneuptime/releases/tag/10.0.42",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/OneUptime/oneuptime/releases/tag/10.0.42"
        }
      ],
      "source": {
        "advisory": "GHSA-5w5c-766x-265g",
        "discovery": "UNKNOWN"
      },
      "title": "OneUptime SSO: Multi-Assertion Identity Injection via Decoupled Signature Verification"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-34840",
    "datePublished": "2026-04-02T18:52:48.274Z",
    "dateReserved": "2026-03-30T20:52:53.284Z",
    "dateUpdated": "2026-04-02T20:20:13.291Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-34840",
      "date": "2026-07-29",
      "epss": "0.00264",
      "percentile": "0.18194"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-34840\",\"sourceIdentifier\":\"security-advisories@github.com\",\"published\":\"2026-04-02T20:16:28.357\",\"lastModified\":\"2026-07-24T21:10:00.143\",\"vulnStatus\":\"Analyzed\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"OneUptime is an open-source monitoring and observability platform. Prior to version 10.0.42, OneUptime\u0027s SAML SSO implementation (App/FeatureSet/Identity/Utils/SSO.ts) has decoupled signature verification and identity extraction. isSignatureValid() verifies the first \u003cSignature\u003e element in the XML DOM using xml-crypto, while getEmail() always reads from assertion[0] via xml2js. An attacker can prepend an unsigned assertion containing an arbitrary identity before a legitimately signed assertion, resulting in authentication bypass. This issue has been patched in version 10.0.42.\"},{\"lang\":\"es\",\"value\":\"OneUptime es una plataforma de monitoreo y observabilidad de c\u00f3digo abierto. Antes de la versi\u00f3n 10.0.42, la implementaci\u00f3n de SAML SSO de OneUptime (App/FeatureSet/Identity/Utils/SSO.ts) hab\u00eda desacoplado la verificaci\u00f3n de firma y la extracci\u00f3n de identidad. isSignatureValid() verifica el primer elemento \u003cSignature\u003e en el DOM XML usando xml-crypto, mientras que getEmail() siempre lee de assertion[0] a trav\u00e9s de xml2js. Un atacante puede anteponer una aserci\u00f3n sin firmar que contenga una identidad arbitraria antes de una aserci\u00f3n leg\u00edtimamente firmada, lo que resulta en una omisi\u00f3n de autenticaci\u00f3n. Este problema ha sido parcheado en la versi\u00f3n 10.0.42.\"}],\"affected\":[{\"source\":\"security-advisories@github.com\",\"affectedData\":[{\"vendor\":\"OneUptime\",\"product\":\"oneuptime\",\"versions\":[{\"version\":\"\u003c 10.0.42\",\"status\":\"affected\"}]}]}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"security-advisories@github.com\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N\",\"baseScore\":8.1,\"baseSeverity\":\"HIGH\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"HIGH\",\"integrityImpact\":\"HIGH\",\"availabilityImpact\":\"NONE\"},\"exploitabilityScore\":2.8,\"impactScore\":5.2}],\"ssvcV203\":[{\"source\":\"134c704f-9b21-4f2e-91b3-4a467353bcc0\",\"ssvcData\":{\"timestamp\":\"2026-04-02T20:20:03.529115Z\",\"id\":\"CVE-2026-34840\",\"options\":[{\"exploitation\":\"poc\"},{\"automatable\":\"no\"},{\"technicalImpact\":\"total\"}],\"role\":\"CISA Coordinator\",\"version\":\"2.0.3\"}}]},\"weaknesses\":[{\"source\":\"security-advisories@github.com\",\"type\":\"Secondary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-347\"}]}],\"configurations\":[{\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:a:hackerbay:oneuptime:*:*:*:*:*:*:*:*\",\"versionEndExcluding\":\"10.0.42\",\"matchCriteriaId\":\"4F312DCA-BDD5-465F-9848-5CD35CDFC185\"}]}]}],\"references\":[{\"url\":\"https://github.com/OneUptime/oneuptime/commit/2fd7ede52f60444710628d6c1b34dee2ef9e57d1\",\"source\":\"security-advisories@github.com\",\"tags\":[\"Patch\"]},{\"url\":\"https://github.com/OneUptime/oneuptime/releases/tag/10.0.42\",\"source\":\"security-advisories@github.com\",\"tags\":[\"Product\",\"Release Notes\"]},{\"url\":\"https://github.com/OneUptime/oneuptime/security/advisories/GHSA-5w5c-766x-265g\",\"source\":\"security-advisories@github.com\",\"tags\":[\"Exploit\",\"Mitigation\",\"Vendor Advisory\"]}]}}",
    "redhat_vex": {
      "current_release_date": "2026-04-03T23:01:54+00:00",
      "cve": "CVE-2026-34840",
      "id": "CVE-2026-34840",
      "initial_release_date": "2026-01-01T00:00:00+00:00",
      "product_status:known_not_affected": "1",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "OneUptime SSO: Multi-Assertion Identity Injection via Decoupled Signature Verification",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-34840.json",
      "version": "3"
    },
    "vulnrichment": {
      "containers": "{\"adp\": [{\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-34840\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"poc\"}, {\"Automatable\": \"no\"}, {\"Technical Impact\": \"total\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-04-02T20:20:03.529115Z\"}}}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-04-02T20:20:08.122Z\"}}], \"cna\": {\"title\": \"OneUptime SSO: Multi-Assertion Identity Injection via Decoupled Signature Verification\", \"source\": {\"advisory\": \"GHSA-5w5c-766x-265g\", \"discovery\": \"UNKNOWN\"}, \"metrics\": [{\"cvssV3_1\": {\"scope\": \"UNCHANGED\", \"version\": \"3.1\", \"baseScore\": 8.1, \"attackVector\": \"NETWORK\", \"baseSeverity\": \"HIGH\", \"vectorString\": \"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N\", \"integrityImpact\": \"HIGH\", \"userInteraction\": \"NONE\", \"attackComplexity\": \"LOW\", \"availabilityImpact\": \"NONE\", \"privilegesRequired\": \"LOW\", \"confidentialityImpact\": \"HIGH\"}}], \"affected\": [{\"vendor\": \"OneUptime\", \"product\": \"oneuptime\", \"versions\": [{\"status\": \"affected\", \"version\": \"\u003c 10.0.42\"}]}], \"references\": [{\"url\": \"https://github.com/OneUptime/oneuptime/security/advisories/GHSA-5w5c-766x-265g\", \"name\": \"https://github.com/OneUptime/oneuptime/security/advisories/GHSA-5w5c-766x-265g\", \"tags\": [\"x_refsource_CONFIRM\"]}, {\"url\": \"https://github.com/OneUptime/oneuptime/commit/2fd7ede52f60444710628d6c1b34dee2ef9e57d1\", \"name\": \"https://github.com/OneUptime/oneuptime/commit/2fd7ede52f60444710628d6c1b34dee2ef9e57d1\", \"tags\": [\"x_refsource_MISC\"]}, {\"url\": \"https://github.com/OneUptime/oneuptime/releases/tag/10.0.42\", \"name\": \"https://github.com/OneUptime/oneuptime/releases/tag/10.0.42\", \"tags\": [\"x_refsource_MISC\"]}], \"descriptions\": [{\"lang\": \"en\", \"value\": \"OneUptime is an open-source monitoring and observability platform. Prior to version 10.0.42, OneUptime\u0027s SAML SSO implementation (App/FeatureSet/Identity/Utils/SSO.ts) has decoupled signature verification and identity extraction. isSignatureValid() verifies the first \u003cSignature\u003e element in the XML DOM using xml-crypto, while getEmail() always reads from assertion[0] via xml2js. An attacker can prepend an unsigned assertion containing an arbitrary identity before a legitimately signed assertion, resulting in authentication bypass. This issue has been patched in version 10.0.42.\"}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-347\", \"description\": \"CWE-347: Improper Verification of Cryptographic Signature\"}]}], \"providerMetadata\": {\"orgId\": \"a0819718-46f1-4df5-94e2-005712e83aaa\", \"shortName\": \"GitHub_M\", \"dateUpdated\": \"2026-04-02T18:52:48.274Z\"}}}",
      "cveMetadata": "{\"cveId\": \"CVE-2026-34840\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-04-02T20:20:13.291Z\", \"dateReserved\": \"2026-03-30T20:52:53.284Z\", \"assignerOrgId\": \"a0819718-46f1-4df5-94e2-005712e83aaa\", \"datePublished\": \"2026-04-02T18:52:48.274Z\", \"assignerShortName\": \"GitHub_M\"}",
      "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.