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CVE Record

CVE-2026-5724: Missing Authentication on Streaming gRPC Replication Endpoint

The frontend gRPC server's streaming interceptor chain did not include the authorization interceptor. When a ClaimMapper and Authorizer are configured, unary RPCs enforce authentication and authorization, but the streaming AdminService/StreamWorkflowReplicationMessages endpoint accepted requests without credentials. This endpoint is registered on the same port as WorkflowService and cannot be disabled independently. An attacker with network access to the frontend port could open the replication stream without authentication. Data exfiltration is possible, but  only when a configured replication target is correctly configured and the attacker has knowledge of the cluster configuration, as the history service validates cluster IDs and peer membership before returning replication data. The fix was applied per release line: it is present in 1.28.4, 1.29.6, 1.30.4, 1.31.2, and 1.32.0 and later releases on each line. Releases 1.31.0 and 1.31.1 do not contain the fix and are affected. Temporal Cloud is not affected.

MediumCVSS 6.3Not KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

CVE-2026-5724 lets an unauthenticated network user open a Temporal frontend replication stream that should require authorization. The business risk is limited but real: data exposure is possible only in specific replication configurations and with cluster knowledge. Temporal Cloud is not affected.

Executive priority

Treat this as a moderate-priority upgrade for self-hosted Temporal, especially where frontend ports are broadly reachable. The flaw bypasses authentication on one replication stream, but exploitation depends on additional replication and cluster-knowledge conditions.

Technical view

The streaming gRPC path for AdminService/StreamWorkflowReplicationMessages did not include the authorization interceptor. Unary RPCs enforced ClaimMapper and Authorizer checks, but this streaming endpoint accepted unauthenticated requests on the same frontend port as WorkflowService. History service checks on cluster IDs and peer membership limit exploitation conditions.

Likely exposure

Exposure is most likely in self-hosted Temporal deployments running affected 1.28, 1.29, 1.30, or 1.31 releases with reachable frontend gRPC ports. Releases 1.31.0 and 1.31.1 are explicitly affected. Temporal Cloud is stated as not affected.

Exploitation context

No KEV listing is reported in the bundle, and no cited source claims active exploitation. An attacker needs network access to the frontend port. Data exfiltration also requires a correctly configured replication target and knowledge of cluster configuration.

Researcher notes

The vulnerable behavior is specific to the streaming AdminService/StreamWorkflowReplicationMessages endpoint. Do not generalize this to all Temporal RPCs: the source states unary RPCs still enforced authentication and authorization. Evidence does not support claims of active exploitation.

Mitigation direction

  • Upgrade to 1.28.4, 1.29.6, 1.30.4, 1.31.2, 1.32.0, or later applicable releases.
  • Prioritize upgrades for deployments exposing the frontend gRPC port beyond tightly controlled networks.
  • Review Temporal release notes and vendor guidance for the exact release line in use.
  • Reduce network reachability to the frontend port while upgrade work is pending.

Validation and detection

  • Inventory all self-hosted Temporal server versions and identify affected release lines.
  • Confirm whether any deployment is running 1.31.0 or 1.31.1.
  • Check whether frontend gRPC ports are reachable from untrusted networks.
  • Review whether ClaimMapper, Authorizer, and replication targets are configured.
  • After upgrade, verify the deployed version matches a fixed release listed by Temporal.
Prepared
Confidence
high
Sources
6

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

cwe · medium confidence lookup

CWE-306: Credential and account abuse lookup

Authentication and credential weaknesses can make valid-account abuse and credential telemetry useful review starting points. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.

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cve · low confidence lookup

CVE-2026-5724 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

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Vulnerability profileCVE Program record
Severity
Medium
CVSS
6.3 (4.0)
Known Exploited
No
Published

Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:L/SC:L/SI:N/SA:N/S:N/AU:N/R:U/RE:L

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

1CVSS vectors
3Timeline events
1ADP providers
5Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: noneAutomatable: noTechnical Impact: partial

CVSS vector scores

1 official score

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
6.3CVSS 4.0MediumCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:L/SC:L/SI:N/SA:N/S:N/AU:N/R:U/RE:L——Temporal

Vulnerability scoring details

Base CVSS 4.0 score

6.3Medium
CVSS 4.0 vector shape for CVE-2026-5724Attack VectorAttack ComplexityAttack RequirementsPrivileges RequiredUser InteractionVS ConfidentialityVS IntegrityVS AvailabilitySS ConfidentialitySS IntegritySS Availability

Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:L/SC:L/SI:N/SA:N/S:N/AU:N/R:U/RE:L

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Attack Requirements
NonePresent
Privileges Required
NoneLowHigh
User Interaction
NonePassiveActive
VS Confidentiality
HighLowNone
VS Integrity
HighLowNone
VS Availability
HighLowNone
SS Confidentiality
HighLowNone
SS Integrity
HighLowNone
SS Availability
HighLowNone

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. CVE publishedCVE Program

    The CVE record was published.

  3. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CISA-ADPCISA ADP Vulnrichment
other:ssvc

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
Temporal Technologies, Inc.temporaltemporal, 1.24.0, 1.29.0, 1.30.0, 1.31.0unaffected
Weakness

CWE details

CWE-306

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.

CWE-306 · source CWE mapping

Missing Authentication for Critical Function

Missing Authentication for Critical Function represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

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