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)
CWE
- CWE-347 - Improper Verification of Cryptographic Signature
Assigner
References
| URL | Tags | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
|
|||||||||||
{
"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": {
"nvd": "{\"cve\":{\"id\":\"CVE-2026-34840\",\"sourceIdentifier\":\"security-advisories@github.com\",\"published\":\"2026-04-02T20:16:28.357\",\"lastModified\":\"2026-04-03T16:10:23.730\",\"vulnStatus\":\"Undergoing Analysis\",\"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.\"}],\"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}]},\"weaknesses\":[{\"source\":\"security-advisories@github.com\",\"type\":\"Primary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-347\"}]}],\"references\":[{\"url\":\"https://github.com/OneUptime/oneuptime/commit/2fd7ede52f60444710628d6c1b34dee2ef9e57d1\",\"source\":\"security-advisories@github.com\"},{\"url\":\"https://github.com/OneUptime/oneuptime/releases/tag/10.0.42\",\"source\":\"security-advisories@github.com\"},{\"url\":\"https://github.com/OneUptime/oneuptime/security/advisories/GHSA-5w5c-766x-265g\",\"source\":\"security-advisories@github.com\"}]}}",
"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"
}
}
}
Loading…
Loading…
Sightings
| Author | Source | Type | Date |
|---|
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…
Loading…