CVE-2026-21621

Published: Mar 05, 2026 Last Modified: Mar 09, 2026
ExploitDB:
Other exploit source:
Google Dorks:
HIGH 7,0
Source: 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
Attack Vector: network
Attack Complexity: low
Privileges Required: low
User Interaction: none
Confidentiality: N/A
Integrity: N/A
Availability: N/A

Description

AI Translation Available

Incorrect Authorization vulnerability in hexpm hexpm/hexpm ('Elixir.HexpmWeb.API.OAuthController' module) allows Privilege Escalation.

An API key created with read-only permissions (domain: 'api', resource: 'read') can be escalated to full write access under specific conditions.

When exchanging a read-only API key via the OAuth client_credentials grant, the resource qualifier is ignored. The resulting JWT receives the broad 'api' scope instead of the expected 'api:read' scope. This token is therefore treated as having full API access.

If an attacker is able to obtain a victim's read-only API key and a valid 2FA (TOTP) code for the victim account, they can use the incorrectly scoped JWT to create a new full-access API key with unrestricted API permissions that does not expire by default and can perform write operations such as publishing, retiring, or modifying packages.

This vulnerability is associated with program files lib/hexpm_web/controllers/api/oauth_controller.ex and program routines 'Elixir.HexpmWeb.API.OAuthController':validate_scopes_against_key/2.

This issue affects hexpm: from 71829cb6f6559bcceb1ef4e43a2fb8cdd3af654b before 71c127afebb7ed7cc637eb231b98feb802d62999.

EPSS (Exploit Prediction Scoring System)

Trend Analysis

EPSS (Exploit Prediction Scoring System)

Prevede la probabilità di sfruttamento basata su intelligence sulle minacce e sulle caratteristiche della vulnerabilità.

EPSS Score
0,0003
Percentile
0,1th
Updated

EPSS Score Trend (Last 10 Days)

863

Incorrect Authorization

Incomplete
Abstraction: Class Structure: Simple
Common Consequences
Security Scopes Affected:
Confidentiality Integrity Access Control Availability
Potential Impacts:
Read Application Data Read Files Or Directories Modify Application Data Modify Files Or Directories Gain Privileges Or Assume Identity Bypass Protection Mechanism Execute Unauthorized Code Or Commands Dos: Crash, Exit, Or Restart Dos: Resource Consumption (Cpu) Dos: Resource Consumption (Memory) Dos: Resource Consumption (Other)
Applicable Platforms
Technologies: Database Server, Not Technology-Specific, Web Server
Likelihood of Exploit: High
View CWE Details
https://github.com/hexpm/hexpm/commit/71c127afebb7ed7cc637e…
https://github.com/hexpm/hexpm/commit/71c127afebb7ed7cc637eb231b98feb802d62999
https://github.com/hexpm/hexpm/security/advisories/GHSA-739…
https://github.com/hexpm/hexpm/security/advisories/GHSA-739m-8727-j6w3