Vulnerability-Lookup

GHSA-PV35-7W89-V65C

Vulnerability from github – Published: 2026-09-21 12:32 – Updated: 2026-09-21 12:32

Details

Temporal Server did not bound the work performed while searching for a Schedule's next action time. An authenticated caller with namespace write permission could create or update a Schedule that combines a fine-grained cadence with an exclusion calendar that rejects every candidate time, causing the server to evaluate excluded candidates without a per-search work budget. This can consume excessive CPU in Frontend and Schedule worker components. A persisted specification can also cause its backing Schedule Workflow to repeatedly fail and retry, allowing CPU consumption to continue without additional requests until the Schedule is deleted or its backing Workflow is terminated. Repeated or parallel exploitation can deny service. The issue affects availability only; it does not expose or modify Workflow data.

Severity

7.1 (High)


                  
                    CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

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{
  "affected": [],
  "aliases": [
    "CVE-2026-16652"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-606"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-09-21T12:17:10Z",
    "severity": "HIGH"
  },
  "details": "Temporal Server did not bound the work performed while searching for a Schedule\u0027s next action time. An authenticated caller with namespace write permission could create or update a Schedule that combines a fine-grained cadence with an exclusion calendar that rejects every candidate time, causing the server to evaluate excluded candidates without a per-search work budget. This can consume excessive CPU in Frontend and Schedule worker components. A persisted specification can also cause its backing Schedule Workflow to repeatedly fail and retry, allowing CPU consumption to continue without additional requests until the Schedule is deleted or its backing Workflow is terminated. Repeated or parallel exploitation can deny service. The issue affects availability only; it does not expose or modify Workflow data.",
  "id": "GHSA-pv35-7w89-v65c",
  "modified": "2026-09-21T12:32:37Z",
  "published": "2026-09-21T12:32:37Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-16652"
    },
    {
      "type": "WEB",
      "url": "https://github.com/temporalio/temporal/pull/11014"
    },
    {
      "type": "WEB",
      "url": "https://github.com/temporalio/temporal/commit/c10c730e53ae394fffaefe44ba3722150fe40720"
    },
    {
      "type": "WEB",
      "url": "https://github.com/temporalio/temporal/releases/tag/v1.30.7"
    },
    {
      "type": "WEB",
      "url": "https://github.com/temporalio/temporal/releases/tag/v1.31.3"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/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",
      "type": "CVSS_V4"
    }
  ]
}

CVE-2026-16652 (GCVE-0-2026-16652)

Vulnerability from cvelistv5 – Published: 2026-09-21 11:23 – Updated: 2026-09-21 15:33

Title

Temporal Server Schedule exclusion search can cause excessive CPU consumption

Summary

Severity

7.1 (High)


                        
                          CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-09-21 15:32 UTC

CWE

CWE-606 - Unchecked Input for Loop Condition

Assigner

Temporal mitre root

References

4 references

URL	Tags
https://github.com/temporalio/temporal/pull/11014	patch
https://github.com/temporalio/temporal/commit/c10…	patch
https://github.com/temporalio/temporal/releases/t…	release-notes
https://github.com/temporalio/temporal/releases/t…	release-notes

Impacted products

1 product

Vendor	Product	Version
Temporal Technologies, Inc.	Temporal Server	Affected: 1.17.0 , ≤ 1.29.7 (semver) Affected: 1.30.0 , < 1.30.7 (semver) Affected: 1.31.0 , < 1.31.3 (semver) cpe:2.3:a:temporal:temporal::::::::

Credits

An external security researcher who reported this issue responsibly to Temporal Technologies

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-16652",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-09-21T15:32:53.335177Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-09-21T15:33:15.387Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "collectionURL": "https://pkg.go.dev",
          "cpes": [
            "cpe:2.3:a:temporal:temporal:*:*:*:*:*:*:*:*"
          ],
          "defaultStatus": "unaffected",
          "modules": [
            "Schedules"
          ],
          "packageName": "go.temporal.io/server",
          "product": "Temporal Server",
          "programFiles": [
            "service/worker/scheduler/spec.go"
          ],
          "programRoutines": [
            {
              "name": "CompiledSpec.GetNextTime"
            }
          ],
          "repo": "https://github.com/temporalio/temporal",
          "vendor": "Temporal Technologies, Inc.",
          "versions": [
            {
              "lessThanOrEqual": "1.29.7",
              "status": "affected",
              "version": "1.17.0",
              "versionType": "semver"
            },
            {
              "lessThan": "1.30.7",
              "status": "affected",
              "version": "1.30.0",
              "versionType": "semver"
            },
            {
              "lessThan": "1.31.3",
              "status": "affected",
              "version": "1.31.0",
              "versionType": "semver"
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        }
      ],
      "configurations": [
        {
          "lang": "en",
          "supportingMedia": [
            {
              "base64": false,
              "type": "text/html",
              "value": "\u003cp\u003eIn Temporal Server 1.17.x, Schedule APIs were disabled by default and the issue was reachable only when frontend.enableSchedules was enabled. Schedule APIs are enabled by default beginning in 1.18.0. In fixed releases, scheduler.specMaxIterations must remain positive. Setting it to zero or a negative value disables the hard work bound.\u003c/p\u003e"
            }
          ],
          "value": "In Temporal Server 1.17.x, Schedule APIs were disabled by default and the issue was reachable only when frontend.enableSchedules was enabled. Schedule APIs are enabled by default beginning in 1.18.0. In fixed releases, scheduler.specMaxIterations must remain positive. Setting it to zero or a negative value disables the hard work bound."
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            {
              "base64": false,
              "type": "text/html",
              "value": "\u003cp\u003eTemporal Server did not bound the work performed while searching for a Schedule\u0027s next action time. An authenticated caller with namespace write permission could create or update a Schedule that combines a fine-grained cadence with an exclusion calendar that rejects every candidate time, causing the server to evaluate excluded candidates without a per-search work budget. This can consume excessive CPU in Frontend and Schedule worker components. A persisted specification can also cause its backing Schedule Workflow to repeatedly fail and retry, allowing CPU consumption to continue without additional requests until the Schedule is deleted or its backing Workflow is terminated. Repeated or parallel exploitation can deny service. The issue affects availability only; it does not expose or modify Workflow data.\u003c/p\u003e"
            }
          ],
          "value": "Temporal Server did not bound the work performed while searching for a Schedule\u0027s next action time. An authenticated caller with namespace write permission could create or update a Schedule that combines a fine-grained cadence with an exclusion calendar that rejects every candidate time, causing the server to evaluate excluded candidates without a per-search work budget. This can consume excessive CPU in Frontend and Schedule worker components. A persisted specification can also cause its backing Schedule Workflow to repeatedly fail and retry, allowing CPU consumption to continue without additional requests until the Schedule is deleted or its backing Workflow is terminated. Repeated or parallel exploitation can deny service. The issue affects availability only; it does not expose or modify Workflow data."
        }
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        {
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            {
              "lang": "en",
              "value": "Availability degradation or denial of service caused by excessive CPU consumption and a persistent Schedule retry condition. No confidentiality or integrity impact was identified."
            }
          ]
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "Automatable": "NOT_DEFINED",
            "Recovery": "NOT_DEFINED",
            "Safety": "NOT_DEFINED",
            "attackComplexity": "LOW",
            "attackRequirements": "NONE",
            "attackVector": "NETWORK",
            "baseScore": 7.1,
            "baseSeverity": "HIGH",
            "exploitMaturity": "NOT_DEFINED",
            "privilegesRequired": "LOW",
            "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:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "HIGH",
            "vulnConfidentialityImpact": "NONE",
            "vulnIntegrityImpact": "NONE",
            "vulnerabilityResponseEffort": "NOT_DEFINED"
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        "orgId": "61241ed8-fa44-4f23-92db-b8c443751968",
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        {
          "name": "Fix pull request",
          "tags": [
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          ],
          "url": "https://github.com/temporalio/temporal/pull/11014"
        },
        {
          "name": "Fix commit",
          "tags": [
            "patch"
          ],
          "url": "https://github.com/temporalio/temporal/commit/c10c730e53ae394fffaefe44ba3722150fe40720"
        },
        {
          "name": "Temporal Server 1.30.7",
          "tags": [
            "release-notes"
          ],
          "url": "https://github.com/temporalio/temporal/releases/tag/v1.30.7"
        },
        {
          "name": "Temporal Server 1.31.3",
          "tags": [
            "release-notes"
          ],
          "url": "https://github.com/temporalio/temporal/releases/tag/v1.31.3"
        }
      ],
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          "supportingMedia": [
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            }
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        }
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      "title": "Temporal Server Schedule exclusion search can cause excessive CPU consumption",
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            }
          ],
          "value": "Until upgrading, set frontend.enableSchedules to false for namespaces that do not require Schedules. This prevents new Schedule API triggers but does not repair already-running problematic Schedules. For namespaces that must retain the feature, restrict Schedule creation and update to trusted principals and delete Schedules whose exclusions prevent next-action computation from completing. Rate limiting alone is insufficient because it does not bound the work caused by one accepted evaluation."
        }
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    "datePublished": "2026-09-21T11:23:47.298Z",
    "dateReserved": "2026-07-22T18:08:55.806Z",
    "dateUpdated": "2026-09-21T15:33:15.387Z",
    "state": "PUBLISHED"
  },
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}

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.

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GHSA-PV35-7W89-V65C

CVE-2026-16652 (GCVE-0-2026-16652)

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Nomenclature

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