Which versions of Hexpm are affected by CVE-2026-21621?

CVE-2026-21621 presents moderate security risk, a incorrect authorization vulnerability rated CVSS 5.3. Attackers could gain access beyond their authorized level.

How to fix or mitigate CVE-2026-21621?

Within 30 days: Identify affected systems and apply vendor patches as part of regular patch cycle. Monitor vendor channels for patch availability.

Hexpm CVE-2026-21621

Q: What is the CVSS score of CVE-2026-21621?

CVE-2026-21621 has a CVSS 4.0 base score of 7.0 (High). CVSS vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:H/VA:L/SC:N/SI:H/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X. EPSS exploitation probability: 0.0%.

HIGH

Incorrect Authorization (CWE-863)

2026-03-05 6b3ad84c-e1a6-4bf7-a703-f496b71e49db

Privilege Escalation Authentication Bypass Hexpm

7.0

CVSS 4.0 · NVD

Severity by source

NVD PRIMARY

7.0 HIGH

CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:H/VA:L/SC:N/SI:H/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:H/VA:L/SC:N/SI:H/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Lifecycle Timeline

Analysis Generated

Mar 12, 2026 - 22:06 vuln.today

CVE Published

Mar 05, 2026 - 20:16 nvd

HIGH 7.0

DescriptionCVE.org

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.

AnalysisAI

Hexpm's OAuth implementation fails to enforce read-only API key restrictions during token exchange, allowing an attacker with a victim's read-only API key and valid 2FA code to obtain a full-access API key with unrestricted permissions. This privilege escalation vulnerability affects users of the Hexpm package repository and enables unauthorized modification of packages and account settings. No patch is currently available.

Technical ContextAI

This vulnerability (CWE-863: Incorrect Authorization) affects from 71829cb6f6559bcceb1ef4e43a2fb8cdd3af654b. 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.