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

> An attacker with network access can bypass authentication on the streaming replication endpoint to potentially exfiltrate data if replication is configured.

- **Severity:** Medium 6.3 (`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`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 10 Apr 2026
- **Updated:** 8 Jul 2026
- **Also known as:** CLEANSTART-2026-AW40978, CLEANSTART-2026-ED75868, CLEANSTART-2026-HK90516, ECHO-0bd4-bfde-70a9, GHSA-q98v-9f9w-f49q, GO-2026-5578, MINI-4vq3-gjcq-2v4f, MINI-53g3-8j8p-hrg5, MINI-8wpp-fm4r-3gq6, MINI-fjph-m667-f7cf, MINI-fmmc-w32v-p3hw, MINI-hpj9-r8w3-p3vc, MINI-jp2w-3rgm-85vc, MINI-phwj-xf6g-pmcg

## What is CVE-2026-5724?

CVE-2026-5724 is a medium-severity missing authorization vulnerability in temporal, published on 10 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

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.

Weakness: CWE-306 (Missing Authentication for Critical Functionality)

## Which versions are affected by CVE-2026-5724?

7 open source packages ship an affected version, including go.temporal.io/server.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `go.temporal.io/server` | Go | All versions | 1.28.4, 1.29.6, 1.30.4 |
| `go.temporal.io/server` | Go | All versions | 1.28.4 |
| `go.temporal.io/server` | Go | All versions | 1.28.4 |
| `go.temporal.io/server` | Go | From 1.29.0-135.0 | 1.29.6 |
| `go.temporal.io/server` | Go | From 1.29.0-135.0 | 1.29.6 |
| `go.temporal.io/server` | Go | From 1.30.0-143.0 | 1.30.4 |
| `go.temporal.io/server` | Go | From 1.30.0-143.0 | 1.30.4 |

## How do I fix CVE-2026-5724?

Upgrade go.temporal.io/server to a fixed version for your release line: 1.28.4, 1.29.6 or 1.30.4.

## Is CVE-2026-5724 being exploited?

There is no known exploitation of CVE-2026-5724 in the wild and no public exploit code.

Public exploit code:

- https://github.com/tibrn/CVE-2026-5724 (github_poc): https://github.com/tibrn/CVE-2026-5724

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-5724 and fix it if it is affected.

What it is: CVE-2026-5724 is a medium-severity missing authorization vulnerability in temporal, published on 10 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-5724 in the wild and no public exploit code.

Affected packages and fixed versions:
- go.temporal.io/server (Go): affected all versions; fixed in 1.28.4, 1.29.6, 1.30.4
- go.temporal.io/server (Go): affected all versions; fixed in 1.28.4
- go.temporal.io/server (Go): affected all versions; fixed in 1.28.4
- go.temporal.io/server (Go): affected from 1.29.0-135.0; fixed in 1.29.6
- go.temporal.io/server (Go): affected from 1.29.0-135.0; fixed in 1.29.6
- go.temporal.io/server (Go): affected from 1.30.0-143.0; fixed in 1.30.4
- go.temporal.io/server (Go): affected from 1.30.0-143.0; fixed in 1.30.4

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-5724/ (Markdown: https://insights.sbomify.com/CVE-2026-5724/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-5724
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-5724
- OSV: https://osv.dev/vulnerability/CVE-2026-5724

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-5724/
Summaries are generated and may contain mistakes; the official description above is the record.