piccolo-admin has a privilege escalation issue - admin to superuser via session-token disclosure in GET /api/tables/sessions/.

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

8.8 · CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS

• CVE-2026-55485: 0.56% estimated exploitation activity in the next 30 days; percentile 46.94 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary piccoloadmin uses a helper called superuservalidators to gate access to the user and session tables for non-superusers. The helper rejects PUT, PATCH, DELETE, and POST, but does not reject GET. The sessions table stores live session tokens in plaintext, and the token column is not marked secret=True, so it is included in every GET response. Any non-superuser admin can therefore list every other user's live session token with one request, replay the token as their own Cookie: id=…, impersonate that user (including the superuser), and then permanently self-promote by writing superuser = true on their own row. The chain is reachable on a realistic, documented configuration: a deployer adds the Sessions (and User) tables to createadmin([...]) so superusers have a UI to monitor and revoke sessions. Affected component - File: piccoloadmin/endpoints.py - Function: superuservalidators (around line 419) The method check is a deny-list instead of an allow-list; GET is absent.…

Published by the source

28 Aug 2026, 18:14 UTC

Last modified by the source

28 Aug 2026, 18:14 UTC

Source last checked

26 Oct 2026, 13:50 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-2gh4-jmwq-rr8w

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# Patch Next advisory brief: CVE-2026-55485

Advisory: piccolo-admin has a privilege escalation issue - admin to superuser via session-token disclosure in GET /api/tables/sessions/.
IDs: CVE-2026-55485, GHSA-2gh4-jmwq-rr8w
Record: https://patchnext.com/advisories/cve-2026-55485 (revision 1, source checked 26 Oct 2026, 13:50 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.8)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: piccolo-admin 1.14.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI piccolo-admin: affected <= 1.13.0; fixed in 1.14.0

## Suggested inspection (read-only)
- `python -m pip show piccolo-admin`: prints the installed version. Run with the environment that serves production active.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on piccolo-admin.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-2gh4-jmwq-rr8w (GitHub-reviewed advisory GHSA-2gh4-jmwq-rr8w lists affected ranges: PyPI piccolo-admin >=0 <=1.13.0)

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