CVE-2026-15389 (GCVE-0-2026-15389)

Vulnerability from cvelistv5 – Published: 2026-07-14 10:10 – Updated: 2026-07-14 12:08
VLAI
Title
Inadequate access control in Sesame Time session management
Summary
A vulnerability relating to insufficient access control has been identified in the session management of the Sesame Time web application and its REST v3 API. The flaw lies in the fact that the system uses the session identifier (USID) as the sole validation mechanism, without verifying whether that identifier legitimately belongs to the user making the request. As a result, an attacker who obtains a valid USID can impersonate a victim’s session and access their confidential information, including emails, user IDs, roles and corporate data. This vulnerability is exacerbated by poor session lifecycle management: new logins generate additional USIDs without revoking the previous ones, allowing multiple active sessions to coexist and thereby expanding the attack surface.
Severity
8.7 (High)
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
SSVC
Exploitation: none Automatable: yes Technical Impact: partial
CISA Coordinator (v2.0.3)
CWE
  • CWE-639 - Authorization bypass through User-Controlled key
Assigner
References
Impacted products
Vendor Product Version
Sesame Time Sesame Time Affected: 0 , < * (custom)
Create a notification for this product.
Date Public
2026-07-14 10:07
Credits
Miguel Jiménez Cámara
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-15389",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-07-14T12:07:58.958824Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-07-14T12:08:21.909Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Sesame Time",
          "vendor": "Sesame Time",
          "versions": [
            {
              "lessThan": "*",
              "status": "affected",
              "version": "0",
              "versionType": "custom"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "Miguel Jim\u00e9nez C\u00e1mara"
        }
      ],
      "datePublic": "2026-07-14T10:07:00.000Z",
      "descriptions": [
        {
          "lang": "en",
          "supportingMedia": [
            {
              "base64": false,
              "type": "text/html",
              "value": "A vulnerability relating to insufficient access control has been identified in the session management of the Sesame Time web application and its REST v3 API. The flaw lies in the fact that the system uses the session identifier (USID) as the sole validation mechanism, without verifying whether that identifier legitimately belongs to the user making the request. As a result, an attacker who obtains a valid USID can impersonate a victim\u2019s session and access their confidential information, including emails, user IDs, roles and corporate data. This vulnerability is exacerbated by poor session lifecycle management: new logins generate additional USIDs without revoking the previous ones, allowing multiple active sessions to coexist and thereby expanding the attack surface."
            }
          ],
          "value": "A vulnerability relating to insufficient access control has been identified in the session management of the Sesame Time web application and its REST v3 API. The flaw lies in the fact that the system uses the session identifier (USID) as the sole validation mechanism, without verifying whether that identifier legitimately belongs to the user making the request. As a result, an attacker who obtains a valid USID can impersonate a victim\u2019s session and access their confidential information, including emails, user IDs, roles and corporate data. This vulnerability is exacerbated by poor session lifecycle management: new logins generate additional USIDs without revoking the previous ones, allowing multiple active sessions to coexist and thereby expanding the attack surface."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "Automatable": "NOT_DEFINED",
            "Recovery": "NOT_DEFINED",
            "Safety": "NOT_DEFINED",
            "attackComplexity": "LOW",
            "attackRequirements": "NONE",
            "attackVector": "NETWORK",
            "baseScore": 8.7,
            "baseSeverity": "HIGH",
            "exploitMaturity": "NOT_DEFINED",
            "privilegesRequired": "NONE",
            "providerUrgency": "NOT_DEFINED",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
            "valueDensity": "NOT_DEFINED",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "NONE",
            "vulnConfidentialityImpact": "HIGH",
            "vulnIntegrityImpact": "NONE",
            "vulnerabilityResponseEffort": "NOT_DEFINED"
          },
          "format": "CVSS",
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
            }
          ]
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-639",
              "description": "CWE-639 Authorization bypass through User-Controlled key",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-07-14T10:10:29.514Z",
        "orgId": "0cbda920-cd7f-484a-8e76-bf7f4b7f4516",
        "shortName": "INCIBE"
      },
      "references": [
        {
          "url": "https://www.incibe.es/en/incibe-cert/notices/aviso/inadequate-access-control-sesame-time-session-management"
        }
      ],
      "solutions": [
        {
          "lang": "en",
          "supportingMedia": [
            {
              "base64": false,
              "type": "text/html",
              "value": "The vulnerability has been fixed by the Sesame Time team in the latest available version.\u003cbr\u003e\u003cbr\u003eThe update includes improvements to the authentication mechanism and strengthens authorisation checks on the server to ensure that each session can only access information associated with the authenticated user."
            }
          ],
          "value": "The vulnerability has been fixed by the Sesame Time team in the latest available version.\n\nThe update includes improvements to the authentication mechanism and strengthens authorisation checks on the server to ensure that each session can only access information associated with the authenticated user."
        }
      ],
      "source": {
        "discovery": "EXTERNAL"
      },
      "title": "Inadequate access control in Sesame Time session management",
      "x_generator": {
        "engine": "Vulnogram 1.0.2"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "0cbda920-cd7f-484a-8e76-bf7f4b7f4516",
    "assignerShortName": "INCIBE",
    "cveId": "CVE-2026-15389",
    "datePublished": "2026-07-14T10:10:29.514Z",
    "dateReserved": "2026-07-10T11:40:35.281Z",
    "dateUpdated": "2026-07-14T12:08:21.909Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-15389\",\"sourceIdentifier\":\"cve-coordination@incibe.es\",\"published\":\"2026-07-14T11:16:48.053\",\"lastModified\":\"2026-07-14T13:18:16.597\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"A vulnerability relating to insufficient access control has been identified in the session management of the Sesame Time web application and its REST v3 API. The flaw lies in the fact that the system uses the session identifier (USID) as the sole validation mechanism, without verifying whether that identifier legitimately belongs to the user making the request. As a result, an attacker who obtains a valid USID can impersonate a victim\u2019s session and access their confidential information, including emails, user IDs, roles and corporate data. This vulnerability is exacerbated by poor session lifecycle management: new logins generate additional USIDs without revoking the previous ones, allowing multiple active sessions to coexist and thereby expanding the attack surface.\"}],\"affected\":[{\"source\":\"cve-coordination@incibe.es\",\"affectedData\":[{\"vendor\":\"Sesame Time\",\"product\":\"Sesame Time\",\"defaultStatus\":\"unaffected\",\"versions\":[{\"version\":\"0\",\"lessThan\":\"*\",\"versionType\":\"custom\",\"status\":\"affected\"}]}]}],\"metrics\":{\"cvssMetricV40\":[{\"source\":\"cve-coordination@incibe.es\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"4.0\",\"vectorString\":\"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/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\":8.7,\"baseSeverity\":\"HIGH\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"attackRequirements\":\"NONE\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"NONE\",\"vulnConfidentialityImpact\":\"HIGH\",\"vulnIntegrityImpact\":\"NONE\",\"vulnAvailabilityImpact\":\"NONE\",\"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\"}}],\"ssvcV203\":[{\"source\":\"134c704f-9b21-4f2e-91b3-4a467353bcc0\",\"ssvcData\":{\"timestamp\":\"2026-07-14T12:07:58.958824Z\",\"id\":\"CVE-2026-15389\",\"options\":[{\"exploitation\":\"none\"},{\"automatable\":\"yes\"},{\"technicalImpact\":\"partial\"}],\"role\":\"CISA Coordinator\",\"version\":\"2.0.3\"}}]},\"weaknesses\":[{\"source\":\"cve-coordination@incibe.es\",\"type\":\"Secondary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-639\"}]}],\"references\":[{\"url\":\"https://www.incibe.es/en/incibe-cert/notices/aviso/inadequate-access-control-sesame-time-session-management\",\"source\":\"cve-coordination@incibe.es\"}]}}",
    "vulnrichment": {
      "containers": "{\"adp\": [{\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-15389\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"none\"}, {\"Automatable\": \"yes\"}, {\"Technical Impact\": \"partial\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-07-14T12:07:58.958824Z\"}}}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-07-14T12:08:12.541Z\"}}], \"cna\": {\"title\": \"Inadequate access control in Sesame Time session management\", \"source\": {\"discovery\": \"EXTERNAL\"}, \"credits\": [{\"lang\": \"en\", \"type\": \"finder\", \"value\": \"Miguel Jim\\u00e9nez C\\u00e1mara\"}], \"metrics\": [{\"format\": \"CVSS\", \"cvssV4_0\": {\"Safety\": \"NOT_DEFINED\", \"version\": \"4.0\", \"Recovery\": \"NOT_DEFINED\", \"baseScore\": 8.7, \"Automatable\": \"NOT_DEFINED\", \"attackVector\": \"NETWORK\", \"baseSeverity\": \"HIGH\", \"valueDensity\": \"NOT_DEFINED\", \"vectorString\": \"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N\", \"exploitMaturity\": \"NOT_DEFINED\", \"providerUrgency\": \"NOT_DEFINED\", \"userInteraction\": \"NONE\", \"attackComplexity\": \"LOW\", \"attackRequirements\": \"NONE\", \"privilegesRequired\": \"NONE\", \"subIntegrityImpact\": \"NONE\", \"vulnIntegrityImpact\": \"NONE\", \"subAvailabilityImpact\": \"NONE\", \"vulnAvailabilityImpact\": \"NONE\", \"subConfidentialityImpact\": \"NONE\", \"vulnConfidentialityImpact\": \"HIGH\", \"vulnerabilityResponseEffort\": \"NOT_DEFINED\"}, \"scenarios\": [{\"lang\": \"en\", \"value\": \"GENERAL\"}]}], \"affected\": [{\"vendor\": \"Sesame Time\", \"product\": \"Sesame Time\", \"versions\": [{\"status\": \"affected\", \"version\": \"0\", \"lessThan\": \"*\", \"versionType\": \"custom\"}], \"defaultStatus\": \"unaffected\"}], \"solutions\": [{\"lang\": \"en\", \"value\": \"The vulnerability has been fixed by the Sesame Time team in the latest available version.\\n\\nThe update includes improvements to the authentication mechanism and strengthens authorisation checks on the server to ensure that each session can only access information associated with the authenticated user.\", \"supportingMedia\": [{\"type\": \"text/html\", \"value\": \"The vulnerability has been fixed by the Sesame Time team in the latest available version.\u003cbr\u003e\u003cbr\u003eThe update includes improvements to the authentication mechanism and strengthens authorisation checks on the server to ensure that each session can only access information associated with the authenticated user.\", \"base64\": false}]}], \"datePublic\": \"2026-07-14T10:07:00.000Z\", \"references\": [{\"url\": \"https://www.incibe.es/en/incibe-cert/notices/aviso/inadequate-access-control-sesame-time-session-management\"}], \"x_generator\": {\"engine\": \"Vulnogram 1.0.2\"}, \"descriptions\": [{\"lang\": \"en\", \"value\": \"A vulnerability relating to insufficient access control has been identified in the session management of the Sesame Time web application and its REST v3 API. The flaw lies in the fact that the system uses the session identifier (USID) as the sole validation mechanism, without verifying whether that identifier legitimately belongs to the user making the request. As a result, an attacker who obtains a valid USID can impersonate a victim\\u2019s session and access their confidential information, including emails, user IDs, roles and corporate data. This vulnerability is exacerbated by poor session lifecycle management: new logins generate additional USIDs without revoking the previous ones, allowing multiple active sessions to coexist and thereby expanding the attack surface.\", \"supportingMedia\": [{\"type\": \"text/html\", \"value\": \"A vulnerability relating to insufficient access control has been identified in the session management of the Sesame Time web application and its REST v3 API. The flaw lies in the fact that the system uses the session identifier (USID) as the sole validation mechanism, without verifying whether that identifier legitimately belongs to the user making the request. As a result, an attacker who obtains a valid USID can impersonate a victim\\u2019s session and access their confidential information, including emails, user IDs, roles and corporate data. This vulnerability is exacerbated by poor session lifecycle management: new logins generate additional USIDs without revoking the previous ones, allowing multiple active sessions to coexist and thereby expanding the attack surface.\", \"base64\": false}]}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-639\", \"description\": \"CWE-639 Authorization bypass through User-Controlled key\"}]}], \"providerMetadata\": {\"orgId\": \"0cbda920-cd7f-484a-8e76-bf7f4b7f4516\", \"shortName\": \"INCIBE\", \"dateUpdated\": \"2026-07-14T10:10:29.514Z\"}}}",
      "cveMetadata": "{\"cveId\": \"CVE-2026-15389\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-07-14T12:08:21.909Z\", \"dateReserved\": \"2026-07-10T11:40:35.281Z\", \"assignerOrgId\": \"0cbda920-cd7f-484a-8e76-bf7f4b7f4516\", \"datePublished\": \"2026-07-14T10:10:29.514Z\", \"assignerShortName\": \"INCIBE\"}",
      "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.